Can Bridge show me what collections an image is in?

Try this instead.

#target bridge

if(BridgeTalk.appName == 'bridge'){

    var FM = new MenuElement('command', 'Find in Collections...', 'at the end of Tools');

    var FC = new MenuElement('command', 'Find in Collections...', 'after Thumbnail/Open', this.menuID);

    }

FM.onSelect = function (){

    collFind();

    }

FC.onSelect = function(){

        collFind();

    }

function collFind(){

    var foundColl = [];

    var j = 0;

    var k = 0;

    try{

        app.synchronousMode = true;

        if(app.document.selectionsLength != 1){

            alert('Please select one file to search for in Collections.');

            return(false);

            }

        else{

            var sFile = app.document.selections;

            var CollList = app.getCollections();

            var sCollList = app.getSmartCollections();

            for(j=0;j < CollList.length; j++){

                if(app.isCollectionMember(CollList, sFile[0])){

                    foundColl = CollList;

                    k++;

                    }

                }

            if(foundColl == ''){

                alert(sFile[0].name + ' is not in any collections');

                return(true);

                }

            else{

                var w = new Window('palette', 'Find in Collections', undefined, {closeButton:true});

                w.preferredSize = [350, 350];

                g = w.add('group', undefined, '');

                g.orientation = 'column';

                g.preferredSize = [300, 150];

                g.alignChildren = ['fill', 'fill'];

                s = g.add('statictext', undefined, '', {multiline: true});

                lb = g.add('listbox', undefined, '', {multiselect:true});

                lb.preferredSize = [250, 125];

                for(j=0;j < foundColl.length; j++){

                    lb.add('item', foundColl.name);

                    }

                g2 = w.add('group', undefined, '');

                g2.orientation = 'row';

                g2.preferredSize = [300, 150];

                g2.alignChildren = ['fill', 'fill'];

                br = g2.add('button', undefined, 'Remove');

                b = g2.add('button', undefined, 'Close');

                s.text = sFile[0].name + ' is in the following collections:\r\r\

                Select collection(s) and click Remove button to remove ' + sFile[0].name + ' from collection(s).';

                g.layout.layout(true);

                g2.layout.layout(true);

                w.layout.layout(true);

                w.show();

                b.onClick = function(){

                    w.close();

                    }

                br.onClick = function(){

                    var m = 'Remove ' + sFile[0].name + ' from Collections?';

                        if(confirm(m)){

                            for(var a in lb.selection){

                                app.removeCollectionMember(foundColl, sFile[0]);

                                lb.remove(lb.selection);

                            }

                        }

                    }

                }

            }

        app.synchronousMode = false;

        }

    catch(e){

        alert(e + '   ' + e.line);

        return;

        }

    }