function Validate(){

	var membertype = document.frm.membertype.value;		
	
	if (membertype == "" || membertype== "0" || membertype == "-1" ||membertype.indexOf("Select") != -1) 
	{
		alert("Please Select User Type");
		document.frm.membertype.focus();	   	
		return false;
	}	
	
	document.frm.action = 'registration.php';
	document.frm.submit();
}
<!--
function MM_openBrWindow(theURL,winName,features) { //v2.0
  window.open(theURL,winName,features);
}
//-->