How to express a SQL null return as a form requirement?

I am processing a form, provided it meets multiple requirements. I am checking a SQL database query, if it is null, I want the form to process.

Here is the query:
$query = mysql_query("SELECT Make, Description FROM somesqldatabase WHERE Description LIKE '$Description'");

while ($row = mysql_fetch_array($query)){
echo("<p>Here is $row["Make"] and $row["Description"]<p>");
}

Here is the form portion that specifies the requirements:
if ("SUBMIT" == $submitform && $row==NULL && $Email == $EmailRetype && $my_form->validate_fields("Make, Description")) {

The $row=NULL portion is hanging things up, I tried $row==0, and different other ways of expressing that "Description does not exist in the database" (already).

Any ideas?

Try this: