Enable Sub-Datasheets In Forms

Hi. I have a table with a subdatasheet enabled showing records from a related table. When I created a datasheet-style form, the option of viewing the sub-datasheet was not carried over and, although the form looks just like the table, there are no little plus signs to click.

How would you go about enabling subdatasheets in a form? It is not critical, but would make things simpler if I could do so. Thanks.

re: Enable Sub-Datasheets In Forms

I found out that you have to set the Source Object Property to an object, but I cannot find this property in the design view of the form. All I see are "Control Source" under the data tab and subdatasheet expanded and subdatasheet size under the general tab. Anyone know where I can find this?