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;}
  }
}

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

function validate_form(thisform)
{
with (thisform)
  {

if (validate_required(first_name,"First Name must be filled out!")==false)
  {first_name.focus();return false;}
else if (validate_required(last_name,"Last Name must be filled out!")==false)
    {last_name.focus();return false;}
else if (validate_email(email,"Email must be valid!")==false)
  {email.focus();return false;}
else if (validate_required(company,"Organisation must be filled out!")==false)
    {company.focus();return false;}
else if (validate_required(phone,"Phone number must be filled out!")==false)
    {phone.focus();return false;}
  }
}