Compile Scripting-javascript skills compatible with IE and FireFox

Writing scripts compatible with IE and FireFox is annoying. Today I 've experienced it again. I. formal expressions
Try to use the following expression to extract the content after the brackets "]" and call the following code in IE normally. FireFox will always replace the content of the double data row with the content of the singular line.
(/(\]) ([^-}] *)/Ig1_.exe c (srcText );
Newtext = "[Department]" + RegExp. $2;
It is confirmed that the problem lies in the "g" of "ig". FireFox treats RegExp as a global variable and does not update $2 in time.
2. Remove Select entries
IE supports select. options. remove (index), while FireFox supports select. remove (index). The compatible method is select. options [I] = null;
3. showModalDialog
FireFox can use showModalDialog. However, if the showModalDialog page has a frame set, the window. dialogArguments for the frame page can be used successfully. FireFox cannot use window. parent. dialogArguments.
Iv. childNodes
FF does not have children. It must be compatible with childNodes, but IE and FF are different. FF regards blank text and line breaks as nodes. To avoid correct nodes obtained by childNodes (index, do not use spaces or line breaks between HTML identifiers.
5. removeChild
FF and node. removeNode (true) cannot be changed to node. parentNode. removeChild (node ).
Vi. outerHTML
FF has no node. outerHTML, when you call node. parentNode. innerHTML is used for special processing. If you only add an event response or set a property value, you can directly add an element. onclick = function () {callxxx (x, y );}
VII. script domain Problems
The cause of this problem is unknown, FF is used