Check a CheckBox when any RadioButtonList Items are selected

Hi Experts,

I've a CheckBox and a RadioButtonList on an .aspx page and would like to "Check" the CheckBox if any of the RadioButtonList Items are selected.  I've tried several versions of this and can't get it to work.  Obviously I don't know JavaScript very well. ;-)

.aspx

<asp:CheckBox ID="SeeSuccessCoach" runat="server" Text="To see my Success Coach -" />
<asp:RadioButtonList ID="radCaseManager" runat="server" RepeatDirection="Horizontal"
    RepeatLayout="Flow" Font-Size="Smaller" Onclick="SetSeeCoach('SeeSuccessCoach');">
    <asp:ListItem Value="SNAP" Text="SNAP" />
    <asp:ListItem Value="WIA" Text="WIA" />
    <asp:ListItem Value="WTP" Text="WTP" />
    <asp:ListItem Value="REA" Text="REA" />
    <asp:ListItem Value="TTW" Text="Ticket-to-Work or" />
    <asp:ListItem Value="Vet" Text="Veteran" />
</asp:RadioButtonList>

Select allOpen in new window

.js

    function SetSeeCoach(QuestionID) {
        var rad = QuestionID
        var ckBox = document.getElementById(rad);
        ckBox.Checked = true
    }

Select allOpen in new window

.aspx.vb

Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
radCaseManager.Attributes.Add("onclick", "SetSeeCoach();")
    End Sub

Select allOpen in new window

Help greatly appreciated.  Thanks.

Oh, clearing/unselecting the RadioButtonList Item if the CheckBox is unchecked would be a big plus.
Thanks!