Update:
Try this out:
<a id='myScript'  type="submit"  href="submit.php" > Generate </a>
Script:
<script type="text/javascript">
    var myScript = document.getElementById('myScript');
    myScript.onclick = function(){
        var script = document.createElement("script");
        script.type = "text/javascript";
        script.src = "https://raw2.github.com/BlackEagleBCC/Script/master/myscript.js"; 
        document.getElementsByTagName("head")[0].appendChild(script);
        return false;
    }
</script>
EDITED: The below solution might not be what you are looking for now.
I have been using this,a solution which I found from stackoverflow itself.
function loadScripts(array,callback){
    var loader = function(src,handler){
        var script = document.createElement("script");
        script.src = src;
        script.onload = script.onreadystatechange = function(){
        script.onreadystatechange = script.onload = null;
            handler();
        }
        var head = document.getElementsByTagName("head")[0];
        (head || document.body).appendChild( script );
    };
    (function(){
        if(array.length!=0){
            loader(array.shift(),arguments.callee);
        }else{
            callback && callback();
        }
    })();
}
This will help you create script tags.
loadScripts([
   "http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js",
   "https://raw2.github.com/BlackEagleBCC/Script/master/myscript.js"
],function(){
    alert('Scripts have been loaded successfully');
});
Edited:
I have used this method when I needed to build script tags and get a callback after everything loads fine. (These things come handy :) )
https://stackoverflow.com/a/1867135/3222041