/* Display email in username text box in Index page*/
emailExp = /^([A-Za-z0-9._%+-]+)@[A-Za-z0-9.-]+\.[A-Za-z]{2,4}$/;
userNameExp = /^[a-zA-Z0-9_-]{8,}$/;
USER_NAME_CHARACTER_MINIMUM = 8;
function createDefaultUserName(id)
{
	var userName = document.getElementById('UserName');
	if (emailExp.test(id.value)) {
		userName.value=id.value.replace(emailExp, "$1");
		for (var i = 1; userName.value.length <= USER_NAME_CHARACTER_MINIMUM; i++) {
			userName.value += i;
		}
	}
}

/* Validate field of Index page*/
function validateSignupForm()
{
     var Email = document.getElementById("Email");
     var UserName = document.getElementById("UserName");

     if(Email.value==""){
       alert("Error: An e-mail address is required!");
       Email.focus();
       return false;
     } else if(!(emailExp.test(Email.value))){
       alert("Error: The e-mail address supplied is not in a valid format, please check the email and try again!");
       Email.focus();
       return false;
     }

     if(UserName.value==""){
       alert("Please enter a username.");
       Email.focus();
       return false;
     } else if(!userNameExp.test(UserName.value)){
	  alert("Error: Your username must be at least eight characters long and may only contain letters, numbers, hyphens, and underscores");
      UserName.focus();
      return false;
	}
	else{
	  document.getElementById('UserNameErr').style.display='none';
	}
	return true;
}