First test the URL that your bookmarklet will try to fetch. Click here.

If it worked, here is the same URL wrapped up in your bookmarklet: Lib. Drag it to your link toolbar.

Base URL: http://www.contra-costa.lib.ca.us/index.html
Vendor: innovative

Bookmarklet text: javascript:var%20re=/([\/-]|is[bs]n=)(\d{7,9}[\dX])/i;if(re.test(location.href)==true) {var%20isbn=RegExp.$2; void(win=window.open('http://cweb.contra-costa.lib.ca.us/cgi-bin/cw_cgi?5500+CONFIGcwp.ini+useDatabase_2100_I_\'+isbn,'LibraryLookup','scrollbars=1,resizable=1,location=1,width=575,height=500'))}

The LibraryLookup project.