Fow Hide Field based on checkbox selection

Hi, 

please forgive my ignorance, but I am new to CRM 2011.

I would like to simply show or hide a field based on whether a checkbox is selected or not.

I have research the following code, but I still cannot get this to work, can someone please point me in the right direction.

the code is:

function ShowHide()

    {
        if(Xrm.Page.getAttribute("tsg_additionaltraining").getValue() == 0)
    {
        Xrm.Page.getControl("tsg_date").setVisible(False);
    }
        else
    {
        Xrm.Page.getControl("tsg_date").setVisible(True);
    }

All I'm then doing is calling the ShowHide function from the OnChange Event.

Thanks in advance for the assistance.

James

James Everson