anonymous code file in IE

Hi,
I have already wasted my couple of hours in this problem. i have 2 drop down in aspx page . both drop down have "onchange" event which i am binding from c# code.
ddlClassHindi.Attributes.Add("onchange", "ChangeSelection(" + ddlClassHindi.ClientID + "," + ddlClassEnglish.ClientID + ")");
ddlClassEnglish.Attributes.Add("onchange", "ChangeSelection(" + ddlClassEnglish.ClientID + "," + ddlClassHindi.ClientID + ")");
function is written in seperate js file "ChangeSelection"
now when i run the page it is giving me error in IE in anonymous code file 
function anonymous(event) {
ValidatorOnChange(event);
ChangeSelection(ctl00_Splitter1Master_ctl01_ctl01_ContentPlaceHolder1_ddlClassHindi,ctl00_Splitter1Master_ctl01_ctl01_ContentPlaceHolder1_ddlClassEnglish)
}
i have drop down control like this :
1. drop down
<asp:DropDownList ID="ddlClassHindi" runat="server" CssClass="d ...