The first thing you need to sort out is that your file has a big fat syntax error in it. A syntax error will prevent the script from doing anything at all because it is not valid PHP
This line is improper syntax:
$query = INSERT INTO website123 (sitetitle, google, keywords, txtcolor, bgdcolor, bgheader, bgleft, bgright, bgfooter, bgmiddle, link, hoverbg, hovertext, inhoud, link1, link2, rechtertekst, footertext) values ("$sitetitle", "$google", "$keywords", "$txtcolor", "$bgdcolor", "$bgheader", "$bgleft", "$bgright", "$bgfooter", "$bgmiddle", "$link", "$hoverbg", "$hovertext", "$inhoud", "$link1", "$link2", "$rechtertekst", "$footertext");
Like weedpacket said, you need to put quotes around your query. Queries are text strings (see [man]string[/man] in the docs). Defining a string that has quotes in it gets tricky because you have to escape any quote marks in your string that are the same as the quote type (single or double) that you used to delineate your string in the first place. Since your string contains many instances of double quotes, I would be inclined to just use single quotes around your query:
$query = 'INSERT INTO website123 (sitetitle, google, keywords, txtcolor, bgdcolor, bgheader, bgleft, bgright, bgfooter, bgmiddle, link, hoverbg, hovertext, inhoud, link1, link2, rechtertekst, footertext) values ("$sitetitle", "$google", "$keywords", "$txtcolor", "$bgdcolor", "$bgheader", "$bgleft", "$bgright", "$bgfooter", "$bgmiddle", "$link", "$hoverbg", "$hovertext", "$inhoud", "$link1", "$link2", "$rechtertekst", "$footertext")';
HOWEVER using single quotes means that each of those variables you have specified in your query will not be evaluated so instead of inserting the contents of the variable $keywords into your database, you would literally be inserting the string $keywords. If you use double quotes to define your string, you must escape each occurrence of double quotes with a backslash like so:
$query="INSERT INTO website123 (sitetitle, google, keywords, txtcolor, bgdcolor, bgheader, bgleft, bgright, bgfooter, bgmiddle, link, hoverbg, hovertext, inhoud, link1, link2, rechtertekst, footertext) values (\"$sitetitle\", \"$google\", \"$keywords\", \"$txtcolor\", \"$bgdcolor\", \"$bgheader\", \"$bgleft\", \"$bgright\", \"$bgfooter\", \"$bgmiddle\", \"$link\", \"$hoverbg\", \"$hovertext\", \"$inhoud\", \"$link1\", \"$link2\", \"$rechtertekst\", \"$footertext\")";
As you can see, it's a bit of a pain in the ass and also quite messy looking.
Another alternative is to put single quotes in your query and use double quotes to define your query string:
$query="INSERT INTO website123 (sitetitle, google, keywords, txtcolor, bgdcolor, bgheader, bgleft, bgright, bgfooter, bgmiddle, link, hoverbg, hovertext, inhoud, link1, link2, rechtertekst, footertext) values ('$sitetitle', '$google', '$keywords', '$txtcolor', '$bgdcolor', '$bgheader', '$bgleft', '$bgright', '$bgfooter', '$bgmiddle', '$link', '$hoverbg', '$hovertext', '$inhoud', '$link1', '$link2', '$rechtertekst', '$footertext')";
Another thing you must do when putting user input into a query is use [/man]mysql_real_escape_string[/man] to escape each variable before you stick it into a query. Otherwise, you'll have a problem if the submitted data contains quotation marks. You will also be vulnerable to sql injection.