function check_valid(f){	

			if(f.fname.value==""){
			alert("First name can not be empty");
			f.fname.focus();
			return false;
			}
			if(f.lname.value==""){
			alert("Last name can not be empty");
			f.lname.focus();
			return false;
			}
				
			if(f.email.value==""){
			alert("The Email Field is Mandatory");
			f.email.focus();
			return false;
			}
				apos=f.email.value.indexOf("@");
				dotpos=f.email.value.lastIndexOf(".");
				lastpos=f.email.value.length-1;
				if (apos < 1 || dotpos - apos < 2 || lastpos - dotpos > 3 || lastpos - dotpos < 2){
				alert("Invalid Email Address");
				f.email.focus();
				return(false);
				}
				
			var pattern="[0-9,-]{5}$";
			if(!f.best_phone.value.match(pattern))
			{
			alert("Please enter correct phone number");
			f.best_phone.focus();
			return false;
			}
			if(f.best_phone.value==""){
			alert("Provide Contact Phone with valid format");
			f.best_phone.focus();
			return false;
			}
				
			/*		
			if(f.lugg.value=="" || isNaN(f.lugg.value)){
			alert("Give the valid Number of Passengers");
			f.lugg.focus();
			return false;
			}
			*/
			if(f.airline.value==""){
			alert("Give the airline Name");
			f.airline.focus();
			return false;
			}
			
			if(f.flight.value==""){
			alert("Give the Flight Time here");
			f.flight.focus();
			return false;
			}
									
			if(f.pickid.value=="select"){
		     	alert("Please Select one from Here");
			    f.pickid.focus();
			    return false;
			    }	
			if(f.timeid.value=="select"){
		     	alert("Please Select one from Here");
			    f.timeid.focus();
			    return false;
			    }		
			if(f.dropoff.value=="select"){
		     	alert("Please Select one from Here");
			    f.dropoff.focus();
			    return false;
			    }
				
				
			if(f.card_numb.value!=""){
			pattern="^[0-9]{15,16}$";
			if(!f.card_numb.value.match(pattern)|| isNaN(f.card_numb.value))
			{
			alert("Please supply Card Number in the valid format");
			f.card_numb.focus();		
			return false;
			}
			}
			if(f.card_numb.value!=""){
			if(f.cardname.value==""){
			alert("The Give Card Name Here");
			f.cardname.focus();
			return false;
			}
			}
			
			if(f.box.checked ==false){
			alert("Please agree with policy and accept the terms");
			f.box.focus();
			return false;
			}				
		
		f.submit();
	
	}