I have two questions about column chooser. firs one is that I'm using header grouping for my grid, for example I have a Display header group with two columns of Type and Size, and also another header Group which name is Storage with two sub columns of Type and size. when I using columnChooser it shows: Type Size Type Size. is there any way to prepend the column header name to them? I also named these columns DS_Size DS_Type ,.... in colModel. is there any way to use these columns colModel name instead of colNames? my second question is that I already using erichynds multiselect (see the link) for my search section and it have conflict with the one which jqGrid use (see also). how can I rename erichynds multiselect plugin to something else? I didn't find any $.fn. in it's source code
I actually asked three questions :P but the first two are one :D
Thank you for reading my questions :)
The answer on your main question you will find in the documentation of jqGrid:
Column Chooser is not compatible with the header grouping
I wrote many parts of the Header Grouping implementation and I know the code of columnChooser. So I know how the code of columnChooser can be modified to include support of Header Grouping. The main problem is that it's relatively much work just to remove the restriction. jqGrid is free open source product. Who are ready to invest his time to remove such limitations? I spend very much my time to help other people on the stackoverflow, but I have to feed my family :-). If you really need such feature you can implement the feature yourself. The most important information which you will need to modify the columnCooser you will find in the answer.
Now about the last part of your question: "conflicts" between who multiselect widgets. Simple look in the list of changes of Eric Hynds jQuery UI MultiSelect Widget (see here) shows that the plugin is alive. On the other side another one (see here) used in columnChooser will be not changed. Nevertheless it works and can be used later. Which "conflicts" exactly you has? In the old version of Eric Hynds jQuery UI MultiSelect Widget it was used the same widget name "ui.multiselect" which was conflict. Many later versions use "ech.multiselect" name (see here). So I don't know which conflicts exactly you mean. Probebly you should just get the last version of the code.
At the end of my answer I would recommend you to read the answer where I suggested some modifications to columnChooser which allows to improve the visibility and to make the dialog of Column Chooser really resizable. One can use just $.jgrid.extend({columnChooser : function(opts) {...}}); to overwrite the original version of columnChooser to the new one.