I have a HTML file
this is not relevant
and a PHP file
OK
in the same folder on the remote server.
Not relevant
From the URL, I call the HTML file
This is meaningless gobbedy-gook
I presume you mean from the browser you call the URL of the HTML file
and the HTML file calls the PHP file when form is submitted.
No it doesn't. I'm guessing the action of a form in the HTML document is the URL of the PHP script.
But it is not going correctly. When I submit the Form, it dislays error:
500 - Internal server error. There is a problem with the resource you are looking for, and it cannot be displayed.
PHP as an interpreted language is unlikely to crash and burn - that's not to say it doesn't happen - just that its rare.
Have you checked the PHP script to see if it might be returning the 500 status message?
Is it only this PHP script which dies like this? i.e. do you have other PHP scripts which don't fall over?
What webserver are you using? Is the interpreter running as a module? CGI? Fast CGI?
What happens if you paste the URL of the PHP script directly into your browser?
Did you try google for "PHP" and the error message? (hint: any of the first 10 of the 514000 results all explain when and why this happens).
C.