function changeInput(input_id, checktext){
	if(checktext == eval("document.getElementById(\'" + input_id + "\').value")){
		eval("document.getElementById(\'" + input_id + "\').value = \"\"");
	}
}

var regExp = /^.+\@.+\..+$/; //Define regular expression for email address validation 

function formSub(my_id){

	if(document.getElementsByName('name')[0].value == "" || document.getElementsByName('name')[0].value == "Name"){
		alert("Please supply your name");
		return false;
	}
	
	if(!document.getElementsByName('email')[0].value.match(regExp)){ //Check email address with regular expression
		alert('The email address you have given is not valid.\nPlease supply a valid email address.');
		return false;
	}
	
	eval("document.getElementById('" + my_id + "').submit();");

}