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(name,"Please provide a name or alias.")==false)
  {name.focus();return false}

if (validate_email(email,"Please provide a valid email address.")==false)
  {email.focus();return false}

if (validate_required(comment,"Please add some comments to this post.")==false)
  {comment.focus();return false}

}
}