Your HTML here

<script>
// self executing function here
(function() {
   // your page initialization code here
   // the DOM will be available here

})();
</script>

function docReady(fn) {
    // see if DOM is already available
    if (document.readyState === "complete" || document.readyState === "interactive") {
        // call on next available tick
        setTimeout(fn, 1);
    } else {
        document.addEventListener("DOMContentLoaded", fn);
    }
}    

docReady(function() {
    // DOM is loaded and ready for manipulation here
});

document.addEventListener('DOMContentLoaded', fn, false);

window.addEventListener('load', fn, false )

document.attachEvent("onreadystatechange", fn);

window.attachEvent("onload", fn);

(function(funcName, baseObj) {
    // The public function name defaults to window.docReady
    // but you can pass in your own object and own function name and those will be used
    // if you want to put them in a different namespace
    funcName = funcName || "docReady";
    baseObj = baseObj || window;
    var readyList = [];
    var readyFired = false;
    var readyEventHandlersInstalled = false;

    // call this when the document is ready
    // this function protects itself against being called more than once
    function ready() {
        if (!readyFired) {
            // this must be set to true before we start calling callbacks
            readyFired = true;
            for (var i = 0; i < readyList.length; i++) {
                // if a callback here happens to add new ready handlers,
                // the docReady() function will see that it already fired
                // and will schedule the callback to run right after
                // this event loop finishes so all handlers will still execute
                // in order and no new ones will be added to the readyList
                // while we are processing the list
                readyList[i].fn.call(window, readyList[i].ctx);
            }
            // allow any closures held by these functions to free
            readyList = [];
        }
    }

    function readyStateChange() {
        if ( document.readyState === "complete" ) {
            ready();
        }
    }

    // This is the one public interface
    // docReady(fn, context);
    // the context argument is optional - if present, it will be passed
    // as an argument to the callback
    baseObj[funcName] = function(callback, context) {
        if (typeof callback !== "function") {
            throw new TypeError("callback for docReady(fn) must be a function");
        }
        // if ready has already fired, then just schedule the callback
        // to fire asynchronously, but right away
        if (readyFired) {
            setTimeout(function() {callback(context);}, 1);
            return;
        } else {
            // add the function and context to the list
            readyList.push({fn: callback, ctx: context});
        }
        // if document already ready to go, schedule the ready function to run
        if (document.readyState === "complete") {
            setTimeout(ready, 1);
        } else if (!readyEventHandlersInstalled) {
            // otherwise if we don't have event handlers installed, install them
            if (document.addEventListener) {
                // first choice is DOMContentLoaded event
                document.addEventListener("DOMContentLoaded", ready, false);
                // backup is window load event
                window.addEventListener("load", ready, false);
            } else {
                // must be IE
                document.attachEvent("onreadystatechange", readyStateChange);
                window.attachEvent("onload", ready);
            }
            readyEventHandlersInstalled = true;
        }
    }
})("docReady", window);

// pass a function reference
docReady(fn);

// use an anonymous function
docReady(function() {
    // code here
});

// pass a function reference and a context
// the context will be passed to the function as the first argument
docReady(fn, context);

// use an anonymous function with a context
docReady(function(context) {
    // code here that can use the context argument that was passed to docReady
}, ctx);

IE6 and up
Firefox 3.6 and up
Chrome 14 and up
Safari 5.1 and up
Opera 11.6 and up
Multiple iOS devices
Multiple Android devices

// with jQuery 
$(document).ready(function(){ /* ... */ });

// shorter jQuery version 
$(function(){ /* ... */ });

// without jQuery (doesn't work in older IEs)
document.addEventListener('DOMContentLoaded', function(){ 
    // your code goes here
}, false);

// and here's the trick (works everywhere)
function r(f){/in/.test(document.readyState)?setTimeout('r('+f+')',9):f()}
// use like
r(function(){
    alert('DOM Ready!');
});

document.addEventListener("DOMContentLoaded", function(event) {
    // Your code to run since DOM is loaded and ready
});

$(document).ready(function() {
    console.log("Ready!");
});

$(function() {
    console.log("ready!");
});

 Example:

(function() {
   // Your page initialization code here  - WRONG
   // The DOM will be available here   - WRONG
})();

document.onreadystatechange = function () {
  var state = document.readyState;
  if (state == 'interactive') {
      init();
  } else if (state == 'complete') {
      initOnCompleteLoad();
  }
}​;

window.readyHandlers = [];
window.ready = function ready(handler) {
  window.readyHandlers.push(handler);
  handleState();
};

window.handleState = function handleState () {
  if (['interactive', 'complete'].indexOf(document.readyState) > -1) {
    while(window.readyHandlers.length > 0) {
      (window.readyHandlers.shift())();
    }
  }
};

document.onreadystatechange = window.handleState;

ready(function () {
  // your code here
});

function ready(fn) {
  if (document.readyState != 'loading'){
    fn();
  } else if (document.addEventListener) {
    document.addEventListener('DOMContentLoaded', fn);
  } else {
    document.attachEvent('onreadystatechange', function() {
      if (document.readyState != 'loading')
        fn();
    });
  }
}

ready(function() { alert('hello'); });

window.onload = function(){
    // Code. . .

}

window.onload = main;

function main(){
    // Code. . .

}

<script>
   myFunction()
</script>

function ready(fn){var d=document;(d.readyState=='loading')?d.addEventListener('DOMContentLoaded',fn):fn();}

ready(function(){
    //some code
});

(function(fn){var d=document;(d.readyState=='loading')?d.addEventListener('DOMContentLoaded',fn):fn();})(function(){

    //Some Code here
    //DOM is avaliable
    //var h1s = document.querySelector("h1");

});

function onReady(yourMethod) {
  var readyStateCheckInterval = setInterval(function() {
    if (document && document.readyState === 'complete') { // Or 'interactive'
      clearInterval(readyStateCheckInterval);
      yourMethod();
    }
  }, 10);
}
// use like
onReady(function() { alert('hello'); } );

function onReady(yourMethod) {
  if (document.readyState === 'complete') { // Or also compare to 'interactive'
    setTimeout(yourMethod, 1); // Schedule to run immediately
  }
  else {
    readyStateCheckInterval = setInterval(function() {
      if (document.readyState === 'complete') { // Or also compare to 'interactive'
        clearInterval(readyStateCheckInterval);
        yourMethod();
      }
    }, 10);
  }
}

// Use like
onReady(function() { alert('hello'); } );

// Or
onReady(functionName);