When I try to use the tag, but $foo_PHP tutorial

When sending a form, it may use an image as a submit button, as shown below:
When the user presses any point on the image When the form is sent back to the server, it also contains two additional variables foo.x and foo.y.
Because foo.x and foo.y are problematic names in PHP, they are automatically converted into variables $foo_x and $foo_y. It is converted during PHP processing.

http://www.bkjia.com/PHPjc/632412.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/632412.htmlTechArticleWhen sending a form, it may use an image as a submit button, as shown below: ＜input type=" image" SRC="image.gif" NAME="foo"＞When the user clicks on any point of the image, accompanied by...