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_email(Email,"Please enter a valid email address!")==false)
{Email.focus();return false;}}}