set textbox's next button click

            string script = @"
            function clickButton(e, buttonid)
            {
            var bt = document.getElementById(buttonid);
            if (typeof bt == 'object')
            {
            if (navigator.appName.indexOf('Microsoft Internet Explorer')>(-1)){
            if (event.keyCode == 13){
            bt.click();
            return false;
            }
            }
            else
            {
            if (e.keyCode == 13)
            {
            bt.click();
            return false;
            }
            }
            }
            } ";
            Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "search", script, true);
            if (this.Request["tab"] == null || this.Request["tab"] == "All Resources")
            {
            this.txtGeneralSearch.Attributes.Add("onkeypress", "return clickButton(event,'" + this.btnSearch.ClientID + "')");
            }