Hi Alex

You are fixing the symptom, not the cause.

>In case m.lcBillNo - "N", m.lcDateIn - "D"
>

Local lcFilter
>lcFilter = "BILLNO=" + Transform( m.lcBillNo) + " AND DATEIN=CTOD('" + DTOC( m.lcDateIn) + "')"
>Set Filter To &lcFilter

>In case m.lcBillNo - "C", m.lcDateIn - "D"
>

Local lcFilter
>lcFilter = "BILLNO='" + AllTrim( m.lcBillNo) + "' AND DATEIN=CTOD('" + DTOC( m.lcDateIn) + "')"
>Set Filter To &lcFilter

>and so on...
>

That is the wrong way to fix this problem.

lcBillNo and lcDateIn are character variables. If the user interface provided numeric and date values, you should fix that when the values are put in the variables.

CTOD will prevent the filter from Rushmore Optimizing.

LOCAL m.lnSelect, m.lcOldFilter, m.lcBillNo, m.lcDateIn
m.lnSelect = SELECT()
SELECT mstr
m.lcOldFilter = FILTER()
m.lcBillNo = TRANSFORM(THISFORM.TEXT1.VALUE) && should be THISFORM.txtBillNo.Value

m.lcDateIn = DTOS(THISFORM.TEXT2.VALUE) && should be THISFORM.txtDateIn.Value

m.lcDateIn = "{^" + LEFT(m.lcDateIn,4) + "-" + SUBSTR(m.lcDateIn,5,2) + "-" ;
  + SUBSTR(m.lcDateIn,7,2) + "}"

lcFilter = "BILLNO = " + m.lcBillNo + " AND DATEIN = " + m.lcDateIn

SET FILTER TO &lcFilter.
LOCATE
IF NOT FOUND()
  SET FILTER TO &lcOldFilter.
ENDIF
SELECT (m.lnSelect)