function validate_email(field,alerttxt)
{
with (field)
  {
var apos=value.indexOf("@");
var 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(senders_name,"Senders name is blank")==false)
  {senders_name.focus();return false;}
  }
  with (thisform)
  {
  if (validate_required(senders_company,"Senders company is blank")==false)
  {senders_company.focus();return false;}
  }
with (thisform)
  {
  if (validate_required(senders_email,"Senders email is blank")==false)
  {senders_email.focus();return false;}
  }

with (thisform)
  {
  if (validate_required(senders_msg,"Senders message is blank")==false)
  {senders_msg.focus();return false;}
  }
with (thisform)
  {
  if (validate_email(senders_email,"Please enter a valid email address!")==false)
    {senders_email.focus();return false;}
  }
 }