// JavaScript Document

function checkForm() {
FirstName = document.getElementById("FirstName").value;
Surname = document.getElementById("Surname").value;
Email = document.getElementById("Email").value;
ContactNumber = document.getElementById("ContactNumber").value;

if (FirstName == "") { 
hideAllErrors();
document.getElementById("FirstNameError").style.display = "inline";
document.getElementById("FirstName").select();
document.getElementById("FirstName").focus();
return false;
  } else if (Surname == "") {
hideAllErrors();
document.getElementById("SurnameError").style.display = "inline";
document.getElementById("Surname").select();
document.getElementById("Surname").focus();
  return false;
    } else if (Email == "") {
hideAllErrors();
document.getElementById("EmailError").style.display = "inline";
document.getElementById("Email").select();
document.getElementById("Email").focus();
  return false;
      } else if (ContactNumber == "") {
hideAllErrors();
document.getElementById("ContactNumberError").style.display = "inline";
document.getElementById("ContactNumber").select();
document.getElementById("ContactNumber").focus();
  return false;
  }
  return true;
  }
 
  function hideAllErrors() {
document.getElementById("FirstNameError").style.display = "none"
document.getElementById("SurnameError").style.display = "none"
document.getElementById("EmailError").style.display = "none"
document.getElementById("ContactNumberError").style.display = "none"
  }