var error;
var error_f;
var error_l;
var error_p;
var error_fx;
var errormsg;

//--------------------------Customise-------------------------------
var isFirstReq=true; // True if First Name field required else False
var isLastReq=true; // True if Last Name field required else False
var isPhoneReq=true; // True if Phone Number required else False
var isFaxReq=true; // True if Fax Number required else False
//------------------------------------------------------------------

function reset_error()
{
 error_f=false;
 error_l=false;
 error_p=false;
 error_fx=false;
 errormsg='***** You Failed To Complete All Required Fields! *****\n_____________________________\n\n';
}

function validate_first()
{
 if(isFirstReq)
 {
  if(document.main.firstname.value=="")
  {
   errormsg+='Please enter your First Name.\n';
   error_f=true;
   {
    document.main.firstname.focus();
   }
  }
 }
 if(error_f)
 {
  document.main.firstname.select();
 }
}

function validate_last()
{
 if(isLastReq)
 {
  if(document.main.lastname.value=="")
  {
   errormsg+='Please enter your Last Name.\n';
   error_l=true;
   if(!error_f)
   {
    document.main.lastname.focus();
   }
  }
 }
 if((!error_f)&&(!error_l))
 {
  document.main.lastname.select();
 }
}

function validate_phone()
{
 if(isPhoneReq)
 {
  if(document.main.phone.value=="")
  {
   errormsg+='Please enter your Phone Number.\n';
   error_p=true;
   if((!error_f)&&(!error_l))
   {
    document.main.phone.focus();
   }
  }
 }
 if((!error_f)&&(!error_l))
 {
  document.main.phone.select();
 }
}

function validate_fax()
{
 if(isFaxReq)
 {
  if(document.main.fax.value=="")
  {
   errormsg+='Please enter your Fax Number.\n';
   error_fx=true;
   if((!error_f)&&(!error_l)&&(!error_p))
   {
    document.main.fax.focus();
   }
  }
 }
 if((!error_f)&&(!error_l)&&(!error_p))
 {
  document.main.fax.select();
 }
}

function validate()
{
 reset_error();
 validate_first();
 validate_last();
 validate_phone();
 validate_fax();

 if(error_f || error_l || error_p || error_fx)
 {
  error=true;
 }
 else
 {
  error=false;
 }
 if(!error)
 {
  document.main.submit();
 }
 else
 {
  alert(errormsg);
 }
}