Query field name "ResolvedDate" a date field

In the query filter I have this Like [Forms]![frmRptEmailTracking]![txtOS] & "*"

in the form user controls txtos by clicking radio button. when they click radio button then the txtOS says Is Null else it stays blank.

It does not produce any result and I know the query should give me 176 records out of 656 records.

Please suggest

Take a look at the data before and after selecting the txtOS.

A check box will return either zero when unchecked or -1 when checked.