function init() {
	var myObj;
	
	function addFileBox() {
		var fileUpload = document.getElementById("file_upload");
		var childs =  fileUpload.getElementsByTagName("div"); 
		var elementNumber = childs.length + 1;
		var newFileBox, newFileItem;

		newFileBox = document.createElement("div");
		newFileBox.innerHTML += '<input type="file" name="file_' + 
			elementNumber + '" size="50" /><br />';

		/*newFileBox.innerHTML += '<input type="radio" name="file_type_' +
			elementNumber + '" id="xls_' + elementNumber + 
			'" value="xls" checked="checked" /><label for="xls_' + 
			elementNumber + '">Excel</label>';
			
		newFileBox.innerHTML += '<input type="radio" name="file_type_' +
			elementNumber + '" id="gsn_' + elementNumber + 
			'" value="gsn" /><label for="gsn_' + elementNumber + 
			'">Gaussian</label>';
			
		newFileBox.innerHTML += '<input type="radio" name="file_type_' +
			elementNumber + '" id="chm_' + elementNumber + 
			'" value="chm" /><label for="chm_' + elementNumber + 
			'">Charm</label>';*/
	
		fileUpload.appendChild(newFileBox);
	}
	
	function  removeFileBox() {
		var fileUpload = document.getElementById("file_upload");
		var childs =  fileUpload.getElementsByTagName("div");
		var numNodes = childs.length;
		var lastChild;

		if ( numNodes > 1 ) {
			lastChild = childs[childs.length-1];
			fileUpload.removeChild(lastChild);
		}
	}
	function addEvent (element, evType, func, useCapture) {
		if (element.addEventListener) 
		{
			element.addEventListener(evType, func, useCapture);
			return true;
		} else if (element.attachEvent) {
			var r = element.attachEvent('on' + evType, func);
			return r;
		} else {
			element['on' + evType] = func;
		}
	}
	
	myObj = document.getElementById("add");
	addEvent(myObj, "click", addFileBox, false);
	myObj = document.getElementById("remove");
	addEvent(myObj, "click", removeFileBox, false);
	addFileBox();
}
window.onload = init;