New Post: Using SPServices or JQuery to change Control Mode

<SharePoint:FormField runat="server" id="ff5{$Pos}" ControlMode="Display" FieldName="Location" __designer:bind="{ddwrt:DataBind('u',concat('ff5',$Pos),'Value','ValueChanged','ID',ddwrt:EscapeDelims(string(@ID)),'@Location')}"/>

My Location field needs to switch from "Display" to "Edit". Other fields need to change from "Edit" to "Display".

How do I write a JQuery or SPServices function to perform the change when the field is the only parameter?