function ch(){
	with(document.mail){
		if(name.value==""){
			alert("Please Input Your Full Name");
			return false;
		}
		if(email.value==""){
			alert("Please Input Your Email Address");
			return false;
		}
		var mail = email.value;
		if((mail.indexOf("@")==-1)||(mail.indexOf(".")==-1)||(mail.indexOf("@")==0)||(mail.indexOf(".")==0)||(mail.lastIndexOf("@")==mail.length-1)||(mail.lastIndexOf(".")==mail.length-1) ){
 			alert("Please Input Correct Email Address");
 			return false;
		}
		var flag=0;
		for(var i=0; i<tourclass.length; i++){
			if(tourclass[i].checked==true){
			   flag = 1;
			}
		}
		if(flag==0){
			alert("Please Select Tour Class");
			return false;
		}
		
		var regexp = /\d/;
		var adultvalue = adult.value;
		if(!regexp.test(adultvalue)){
			alert("Please Input No. of Adult");
			return false;
		}
		var childvalue = child.value;
		if(!regexp.test(childvalue)){
			alert("Please Input No. of Children");
			return false;
		}
	}
}