If you change the element type from a submit button to an image, and if the Data Assist Search uses the original submit button as the trigger, then the trigger code will need to be updated.
A submit button has a value attribute, whereas an image element does not support passing a value.
Instead, with an image button, it passes the x and y coordinates of where the mouse clicked the image.
for example, the trigger code for a submit button would look like this:
if (isset($_POST["WADbSearch1"])) {
and in the case of your submit button code:
<input type="submit" name="WADbSearch1" Value="GO" style="cursor:pointer; font-size: 30px; color: #fff; background-color: #4879BE; border: none;">
the value of:
<?php echo $_POST["WADbSearch1"]; ?>
would write to the page:
GO
once you change it to an image, the value attribute is no longer valid, so even if you had:
<input type="image" src="images/misc/go.jpg" name="WADbSearch1" class="searchSubmit" value="GO" >
the above echo would not write anything to the page, because no value is passed, instead, there is an x or y coordinate, so to write a value, use:
<?php echo $_POST["WADbSearch1_x"]; ?>
and that will write the x coordinate for where the image was clicked.
so, for the trigger code, it needs to be edited to:
if (isset($_POST["WADbSearch1_x"])) {