3464 Data type mismatch in criteria expression?

Function BuildSQLString(strSQL As String) As Boolean
Dim strWHERE As String
Dim ctl As Control
Dim i As Integer
For Each ctl In Me.Form.Controls
If ctl.ControlType = acTextBox Then
For i = 1 To Me.Form.Controls.Count
If Not IsNull(ctl) Then
If IsNumeric(ctl) Then 'This is a number
strWHERE = strWHERE & " And " & ctl.Name & " = " & ctl
ElseIf IsDate(ctl) Then 'This is a date
strWHERE = strWHERE & " And " & ctl.Name & " =#" & ctl & "#"
Else 'This is text
strWHERE = strWHERE & " And " & ctl.Name & "='" & ctl & "'"
End If
End If
Next i
strWHERE = strWHERE
End If
Next ctl
strSQL = "SELECT * FROM [Lot Specs]"
If strWHERE <> "" Then strSQL = strSQL & " WHERE " & Mid$(strWHERE, 6)
BuildSQLString = True
End Function
 
Private Sub cmdFind_Click()
 
On Error GoTo Err_Handler
Dim strSQL As String
Dim stDocName As String
Dim strMsg As String
Dim strCount As String
stDocName = "qrySearchForm"
 
If Not BuildSQLString(strSQL) Then
MsgBox "There was a problem building the string"
Exit Sub
End If
CurrentDb.QueryDefs(stDocName).SQL = strSQL
RefreshDatabaseWindow
strCount = DCount("*", stDocName)
strMsg = "There are " & strCount & " Records Found" & vbCrLf & vbCrLf & _
"Do You Want To View These Records?"
If MsgBox(strMsg, vbYesNo) = vbYes Then
DoCmd.OpenQuery stDocName, , acReadOnly
End If
Exit_Handler:
Exit Sub
Err_Handler:
MsgBox Err.Number & " " & Err.Description
Resume Exit_Handler
 
End Sub