1     function validate_cvv(cvv){
2
3         var myRe = /^[0-9]{3,4}$/;
4         var myArray = myRe.exec(cvv);
5         if(cvv!=myArray)
6          {
7            alert("Invalid cvv number"); //invalid cvv number
8            return false;
9         }else{
10             return true;  //valid cvv number
11            }
12
13         }
14