How do you access SPGridview ClientID in web part from javascript on the page

Question

I am creating an SPGridView dynamically and adding to my page. It is encased in a web part. How do I access the ClientID of the grid from the javascript on the page?

 function openCommentsDialog( id) {

    try {
        **fails-->**var grid = document.getElementById("_grid");
        //variable to contain the cell of the grid 
        var cell;


        var options = SP.UI.$create_DialogOptions();
        options.url = "SRPChange.aspx" + "?Type=" + type + "&ItemID=" + id;
        options.height = 600;
        options.width = 800;
        options.allowMaximize = false;
        options.Title = "SRP Change Dialog";
        options.args = { Type: type, ItemID: id };

        SP.UI.ModalDialog.showModalDialog(options);
    }
    catch (Err) {
    }
}

Answer 1

Like so: var grid = document.getElementById("<%= _grid.ClientID %>");

in jQuery: $("#<%= _grid.ClientID %>");

Answer 2

I solved this with inline ClientID in javascript