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

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_form(thisform)
{
with (thisform)
{
if (validate_required(FirstName,"Please enter first name.")==false)
{FirstName.focus();return false;}
if (validate_required(LastName,"Please enter last name.")==false)
{LastName.focus();return false;}
if (validate_email(email,"Please enter a valid e-mail address.")==false)
{email.focus();return false;}
if (validate_required(comments,"Please enter your message.")==false)
{comments.focus();return false;}
}
}