How to set values in VLV & BigText

Hi,

I have an extension field with an VLV & Text. I need to reset the value to defaults for VLV & Text. I tried using the below syntax

doc.getExtensionField("XXXX").set(null);

This has resulted in VLV field disappeared from the screen & the Text value remains as entered.

Please suggest

Rgds,

Vinod