function validate_required(field,alerttxt)
{
with (field)
  {
  if (value==null||value=="")
    {
    alert(alerttxt);return false;
    }
  else
    {
    return true;
    }
  }
}





function validatemail(thisform)
{
with (thisform)
  {
  
  if (validate_required(first_name,"You need to enter your first name")==false)
  {first_name.focus();return false;}
  
  if (validate_required(last_name,"You need to enter your surname")==false)
  {last_name.focus();return false;}	
   
  if (validate_email(email,"Not a valid e-mail address!")==false)
  {email.focus();return false;}
  
  if (validate_required(company,"You need to enter your company name")==false)
  {company.focus();return false;}
  
  if (validate_required(telephone,"You need to enter your telephone number")==false)
  {telephone.focus();return false;}
  
  if (validate_required(imgverify,"Please do not leave blank")==false)
  {imgverify.focus();return false;}
  
  }
}



function validate_email(field,alerttxt)
{
with (field)
  {
  apos=value.indexOf("@");
  dotpos=value.lastIndexOf(".");
  if (apos<1||dotpos-apos<2)
    {alert(alerttxt);return false;}
  else {return true;}
  }
}