var ck_name = /^[A-Za-z0-9 ]{3,20}$/;
var ck_email = /^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i 
function validate(form){
var name = form.name.value;
var email = form.email.value;  
var errors = [];

if (!ck_name.test(name)) {
  errors[errors.length] = "Enter Your Full Name .";
 }
 if (!ck_email.test(email)) {
  errors[errors.length] = "You must enter a valid email address.";
 }
 if(form.country.value == "")
    {
       errors[errors.length] ="Please Select Your Country."
    }
 if (errors.length > 0) {
 reportErrors(errors);
 return false;
 } 
 return true;
}

function reportErrors(errors){
 var msg = "Please Enter Valide Data...\n";
 for (var i = 0; i<errors.length; i++) {
  var numError = i + 1;
  msg += "\n" + numError + ". " + errors[i];
 }
 alert(msg);
}