Script and CSS style loader to manage the load order and detect when complete.

script_loader

var numLoaded=0;
var minimumToLoad=1;
  
function loadScript( file, type, title ) {
  	//console.log( "javascript: " + "loadScript: " + file );
		if ( type == 'js' ){ 
			var script = document.createElement( 'script' );
			script.type = 'text/javascript';
			script.src = file;
			if (script.readyState){
				script.onreadystatechange = function(){
					if (script.readyState == "loaded" ||
							script.readyState == "complete"){
						script.onreadystatechange = null;
						loadHandler( title );
					}
				};
			} else {
				script.onload = function(){
					loadHandler( title );
				};
			}
			var firstScriptTag = document.getElementsByTagName( 'script' )[0];
			firstScriptTag.parentNode.insertBefore( script, firstScriptTag );
		} else if ( type == 'css' ){ 
			var script = document.createElement( 'link' );
			script.rel = 'stylesheet';
			script.type = 'text/css';
			script.title = title;
			//script.media = "screen";
			//script.charset = "UTF-8";
			script.href = file;
			document.getElementsByTagName("head")[0].appendChild(script);
		}
	}
  
loadScript ( 'myscript.js', 'js', "myname" );

if ( optionalVariable == true ) {
  minimumToLoad++;
	loadScript ( 'optionalscript.js', 'js', "variablescript" );
}

function loadHandler( name ) {
	numLoaded++;
	//console.log( "javascript: loadHandler: minimumToLoad: " + minimumToLoad + " numLoaded: " + numLoaded + " name: " + name );
	if ( name == "myname" ) {
  	//do something
	}
  if ( numLoaded == minimumToLoad ) {
		//do something
	}
}