Good,but I faced a new problem
for the transaction number I made this
Like [Forms]![Dash Board]![NavigationSubform]![CboTransNum] & "*"
so when the combo box is blank it retrieve the all transaction
the problem that when I request transaction number 1
it gives me 1 , 11, 12, 13, etc
so i tried two ways but both didn't retrieve any thing when combo box is blank
IIf([Forms]![Dash Board]![NavigationSubform]![CboTransNum] Is Null,"",[Forms]![Dash Board]![NavigationSubform]![CboTransNum])
N.B. i tried to put star "*" also not work
Nz([Forms]![Dash Board]![NavigationSubform]![CboTransNum],"")