Search inside extjs tree store

[new]

I have a text field in my tree toolbar that should take a string from a user then search that through a specific column of tree. I use store filter but there is a problem in my code and I dont know what it is. thanks for help. This is my code:

var onSimpleSearch = function(){
 var searchStr= Ext.getCmp('searchField').getValue();
   if(searchStr){
    var tree = Ext.getCmp('infra_tree');
    var tstore = tree.getStore();
    var searchReg = new RegExp(searchStr, 'g');
    console.log(searchReg);
    tstore.filter({property:"ipadd", value:searchStr});
}else {
    Ext.MessageBox.show({
        title: 'Nothing to search',
        msg: 'Search string is empty',
        icon : 'ext-mb-info',
        buttons: Ext.MessageBox.OK
    });
  }
}; 

Erropr: RegEx is not Defined

[skirtle]

Get a stacktrace using Firebug or the Chrome Developer Tools. Should tell you what line the error happens on.

[mankz]

TreeStore has no 'filter' method, you'll need to use cascadeBy(fn) on the root node for now.

[new]

OK, thanks for reply.
We will appreciate if extjs development team implement this feature in future