//Validation for required fileds
function RequiredFieldClientValidation(source, clientside_arguments) {
    var name = clientside_arguments.Value;
    if (name == "") {
        clientside_arguments.IsValid = false;
    }
}

//Validation email function
function EmailClientValidation(source, clientside_arguments) {
   var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/; 

   var address = clientside_arguments.Value;
   if (address == "")
   {
        clientside_arguments.IsValid=false;
        source.attributes.item("errormessage").value = "O E-mail é de preenchimento obrigatório.";
   }
   else
   {    
       clientside_arguments.IsValid=reg.test(address);
       source.attributes.item("errormessage").value = "E-mail invalido.";
   }
}