Neeraj,

Well, I'd need to see the details of SQ1 and SQ2 to really know what's
going on.  But here's the acid text...  make a normal Select query, like
this:
 SELECT [SQ1].*
 FROM [SQ1] INNER JOIN [SQ2] ON [SQ1].Field1 = [SQ2].Field1
 WHERE ((([SQ1].Field2)="Val1"))
... and see if you can add a new record or edit the data in the query
datasheet.  If not, you are dealing with a non-updateable query.  If
this is the case, you might try something like this...
 DELETE [SQ1].*
 FROM [SQ1]
 WHERE (([SQ1].Field2="Val1") AND ([SQ1].Field1 IN(SELECT Field1 FROM
SQ2)))