function checkid() {
	var frm = document.register.username;
	validRegExp=/\W/i;
	validReg=/^[0-9_]/i;

	if (!frm.value){
		alert("Please Enter the Username to check");
		frm.focus();
		return false;
	} else{
			var chk = document.register.username.value;
			//alert(chk);
			if(chk.search(validRegExp)>=0){ alert("Please Enter a valid Username");return false;}
			else if(chk.search(validReg)>=0){ alert("Please Enter a valid Username");return false;}
			window.open('checkid.php?username='+ chk + '','CheckId','widht=300,height=200');
		}
}