What Are the Values Submitted on Image Button Fields? - XHTML 1.0 Tutorials - Understanding Forms and Input Fields

An "image" button input field does not allow viewers to enter any input values directly. But if an "image" button is clicked, the mouse position on the image button will be submitted with other input values to the processing program based on the following rules:

• If an "image" button is not clicked, no values will be submitted for this image button.
• If an "image" button is clicked and no "name" attribute is specified, mouse position in pixel coordinates will be submitted under name x and y as: x=nn&y=nn.
• If a "submit" button is clicked and name="fieldName" attribute is specified, mouse position in pixel coordinates will be submitted under name fieldName.x and fieldName.y as: fieldName.x=nn&fieldName.y=nn.

If you use the previous tutorial example, you can test the following cases:

1. If you click the first image button, you will get the following value submitted:

http://localhost/submit?channel=google&x=31&y=8

2. If you click the second image button, you will get the following values submitted:

http://localhost/submit?channel=google

3. If you push the third submit button, you will get the following values submitted:

http://localhost/submit?channel=google&del.x=18&del.y=8