How to attach refresh event on Dynamic CRM 2011 subgrid using Java Script / JQuery ?

// Attach the function OnFormLoad event
function OnFormLoad() {
    setTimeout("SubGridRefresh();", 2500);
}

function SubGridRefresh() {
    var subgrid = document.getElementById("subgridid");
    if (subgrid.readyState != "complete") {
        // recursive till the subgrid is loaded
        setTimeout(SubGridRefresh, 1000);
        return;
    }
    // if subgrid fully loaded  
    if (subgrid) {
        // attach the name of the custom function to grid
        subgrid.attachEvent("onrefresh", OnRefresh_SubGrid);
        subgrid.control.add_onRefresh(OnRefresh_SubGrid);
    }
}


function OnRefresh_SubGrid() {
    //custom code to execute
    var entityid = Xrm.Page.data.entity.getId();
    alert(entityid);
}