Convert JS datetime to string

hi i've JS.ToString(wdDocMovMagTDATA_DOC.Value); I'm trying to convert a field datetime of a xdatawebdataset to string ... but JS.ToString give me an empty string ! There is other way ?

Is wdDocMovMagTDATA_DOC.Value effectively a JS Date value?
If this is the case Value.toString() should do this.
I do not understand why you would need to do this from a JS Date value from the dataset as the dataset offers the standard Object Pascal interface .asString