In click of cmdSave I have written

IF (thisform.text3.value)>=cheque and thisform.text4.value)<=cheque1
			WAIT window("THIS SERIES OF CHEQUES ALREADY ISSUED!")
	exit
   ENDIF

In chequett table I have cheque and cheque1 fields.

I am getting the error :
Command contains unrerognised phrase/keyword

How I can solve the problem ?