主题：[求助]后台筛选

从后台筛选， 下面代码那里错了， 请老师指教！谢谢！

Dim filter As String
Dim sts() As String = {"产品ID","产品类别","产品名称","产品图号","产品材料","产品规格"}
For Each st As String In sts
    Dim  val As String = e.Form.Controls(st).value
    If val > "" Then
        val = val.Replace("*","[*]")
        If filter = "有图=false " Then
            filter = st & " like '*" & val & "*'"
        Else
            filter = filter & " and " & st & " like '*" & val & "*'"
        End If
    End If
Next
DataTables("产品表").LoadFilter = Filter
DataTables("产品表").Load()