This is the field
<input name="ProductImage" type="file" class="form-control" id="ProductImage" value="<?php echo($Recordset1->getColumnVal("Image")); ?>">
and the update server behavior
$UpdateQuery->bindColumn("Image", "s", "".((isset($_FILES["ProductImage"]))?$_FILES["ProductImage"]["name"]:"") ."", "WA_DEFAULT");
Default file
'DefaultFileName' => "".($Recordset1->getColumnVal("Image")) ."",
the form has the same setting like insert. example
<form method="post" enctype="multipart/form-data" name="form1" id="form1" role="form">