Switching themes... anyone know the variable

[mythic]

Okay, I have been working on getting the template switching mechanism back on track but I don't know what the value is for the mysql statement.

The problem lies within the mysql update code:

$query = "UPDATE {$prefix}settings SET value='$themeurl' WHERE name='themeurl'";

I know that the correct code for changing it is this:looks like this

$query = "UPDATE {$prefix}settings SET value='$themeurl' WHERE name='theme'";

(this code changes the mysql value to a blank field)

One can replace '$themurl' <--- the problem I am running into with whatever template name one wants to lock on. Or change it in mysql.

So if anyone can tell me what the variable is that needs to go there. PLEASE HELP FIX THIS.

Thank you all for reading this.

Edit: After a few moments, I realized that I made this sound like it is the only problem, which it may not be. It may very well be the only problem or one of a few that are preventing this from working. Perhaps the variable is never defined.