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_email(Subscriber,"Not a valid e-mail address")==false)
{Subscriber.focus();return false;}}}