Jeanne Boyarsky wrote:John,
I've never seen a value attribute on an image/submit button before.
The name/value pair of an input type="image" or input type="submit" or button type="submit" element can be used at the server side to distinguish the button pressed. Useful if you've multiple submit buttons in one form. Filling a hidden field and manipulating it with JS is just cumbersome.
Back to actual problem: IE has the behaviour that in case of an input type="image" it will append the name with ".x" and ".y" to represent the position of the mouse cursor at the image.
You can solve it by either using CSS background property to picture a button instead, or to not only check for parameter "name", but also "name.x" if a specific button is pressed.