Help Me fix a Report Using Cascading Combo Boxes

[aamer]

I have made a Cascading Combo Boxes form
this form has 3 combo boxes
its working perfectly

i have to select items in all 3 combo boxes to get a report.

what i want is, if i do not select (leave empty) any item in the third combo box it should give me the report for all the items in the third combo box "Me.SubDesCbo"

how can I do that

I am using the following code:

Private Sub cmdOpenReportSingle_Click()

On Error GoTo Err_Handler

Const REPORTNAME = "Yarn Report"
Const MESSAGETEXT = "All Combo's Must Be Selected."
Dim strCriteria As String

' build string expression to filter report
' to selected customer and account
strCriteria = "[ProcessingStatus] = """ & Me.sldcbo & """" & _
" And [YarnType] = """ & Me.TypeCbo & """" & _
" And [ProcessingSubdescription] = """ & Me.SubDesCbo & """"

' make sure a customer is selected
If Not IsNull(Me.TypeCbo) And Not IsNull(Me.SubDesCbo) Then
' open report filtered to selected customer
DoCmd.OpenReport REPORTNAME, _
View:=acViewPreview, _


WhereCondition:=strCriteria
Else
MsgBox MESSAGETEXT, vbExclamation, "Invalid operation"
End If

Exit_Here:
Exit Sub

Err_Handler:
MsgBox Err.Description, vbExclamation, "Error"
Resume Exit_Here

End Sub

[June7]

Either use parameterized query with wildcards as shown in this tutorial: http://www.datapigtechnologies.com/f...mtoreport.html

Or use conditional If to build the sql string. If control is null, don't concatenate it into the string.