webspace Internal Server Error

[#1]

I get the following error when I go to my webspace.
It may well be that I mistakenly uploaded php files and an .htaccess file which disappeared..
I have emailed the webmaster as advised about 36 hours ago, but no reply as yet.
"Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, webmaster@plus.net and inform them of the time the error occurred, and anything you might have done that may have caused the error."

[#2]

FTP to your website and remove the .htaccess and any recent files and see if the problem goes away - bad .htaccess files can cause this.
Uploading php to the www (homepages) server will not cause this issue, all that would happen is the php file is shown as text in your browser. If this was to your ccgi webspace then a bad php file should not normally cause this, more likely just a blank page.