Not able to get HTML web resource in form load

Need to bind HTML web resource with latest information on form load. but i am not getting web resource in form load. After form load it works fine. pls let me know if you have any idea..

Here is my code

var webResource = Xrm.Page.getControl("MyWebResource");
if (webResource != null && webResource.getObject() != null) {
    var contWindow = webResource.getObject().contentWindow;   
        contWindow.BindData(myobject);
}
webResource.getObject().contentWindow is always returns blank.html.