Internet Explorer Mobile – enable Javascript error reporting
During HTML developing you should enable Javascript Error Warnings:
REGEDIT4 [HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main] "ShowScriptErrors"=dword:00000001
With this setting you will get message boxes if something is wrong with your JavaScript code or the way IEM handles Javascript.
Without this setting IEM will not display any script error and you just get a page that does not work as programmed.