Hi,
no luck even now.
This is what i did.
1 Added TextBox to InfoPath.
2 Added PlaceHolder to this TextBox
3 Added Button to infopath
4 Through VSTA Coding, does this thisXDocument.DOM.selectSingleNode("/my:myFields/my:field1").nodeTypedValue = string.Empty;
5 Preview the form, placeholder is visible
6 click the button, the placeholder is deleted.(although there is no text n the textbox)
Regards,
SaiKrishna