// JavaScript Document
	function clearForm(obj) {
		obj.regex.value = "";
		obj.string.value = "";
		var resultTitle = document.getElementById("resultTitle");
		var resultMsg = document.getElementById("resultMsg");
		if(!isEmpty(resultMsg)) resultMsg.style.display = "none";
		if(!isEmpty(resultTitle)) resultTitle.style.display = "none";
	}
	function doMatch(form) {
		var string = form.string.value;
		var regex = form.regex.value;
		if (isEmpty(regex)) {
			alert("Please enter some regular expression.");
			return false;
		}
		if (isEmpty(form.javascriptRadio.checked)) {
			return true; //regex is in language other than javascript
		}
		if (document.getElementById("resultMsg")) {
				document.getElementById("resultMsg").style.display = "none";
		}		
		if (document.getElementById("resultTitle")) {
				document.getElementById("resultTitle").style.display = "none";
		}
		var result = string.match(regex);
		if (result) {
			alert("OK! The string matches the pattern.");
		} else {
			alert("The string does NOT match the pattern!");
		}
		return false;		
	}