If statement for sql statement

Ok here is my question... I have a form that reads the contents of a directory, places the resulting files into a select box within a form for further processing, code is as follows: <?php $dir_name = "/virtual/path/to/images/directory/"; $dir = opendir($dir_name); $file_list .= "<p><FORM METHOD=\"post\" ACTION=\"index_done.php3\"> <SELECT NAME=\"files\"><OPTION VALUE=\"----------\" NAME=\"----------\">----------</OPTION>"; while ($file_name = readdir($dir)) { if (($file_name != ".") && ($file_name !="..")) { $file_list .= "<OPTION VALUE=\"$file_name\" NAME=\"$file_name\">$file_name</OPTION>"; } } $file_list .= "</SELECT><br><br><INPUT TYPE=\"submit\" NAME=\"submit\" VALUE=\"select\"></FORM></p>"; closedir($dir); ?> This portion works great... now on index_done.php3 it takes the resulting selection and places it into the db table, code is as follows: <?php $file_var = "http://localhost/images/"; $db_name = "database"; $table_name = "image_path"; $connection = @mysql_connect("localhost", "user_name", "password") or die ("Could not connect to database. Please try again later."); $db = @mysql_select_db("$db_name",$connection) or die ("Could not select database table. Please try again later."); $sql = "UPDATE $table_name SET image01_t=\"$file_var$files\""; $result = @mysql_query($sql, $connection) or die ("Could not execute query. Please try again later."); ?> What I need to know is if there is a way to create an if statement that would either update or not update a selected field in the database. Below is a piece I would assume would work however I am not sure of the mysql command to not update anything. Any help would be great. Jas if( $file_name = '----------' ) $sql = "dont update table"; else $sql = "UPDATE $table_name SET image01_t = \"$files\"";