主题：请教：按钮公式问题

If([%年份%]="",MsgBox("请选择年份!",0),if(text([%月份%])="",MsgBox("请选择月份!" ,0),if([%品牌%]="",MsgBox("请选择品牌!",0),if(findrow(text([年份])+"源数据","月份"," <> ",[%月份%],"品牌","=",[%品牌%],"年份","=",[%年份%])=0,MsgBox("源数据中没有相应数据!" ,0) ,ClearGrid(Grid) And AppendFor("指标列表","分公司","分公司","分公司","<> ","")  and DelFor(grid,"分公司","=","") and EvalFor(Grid,"年份","[%年份%]") And EvalFor(Grid,"品牌","[%品牌%]") And EvalFor(Grid,"月份","[%月份%]") And RecalcGrid("按月份",1) And SetRowHeight(26)))))
     我在录入窗口选择年份　月份　品牌后，如果＂2007源数据＂表中没有10月份数据，应显示"源数据中没有相应数据!＂，但实际操作中，语句if(findrow(text([年份])+"源数据","月份"," <> ",[%月份%],"品牌","=",[%品牌%],"年份","=",[%年份%])=0,MsgBox("源数据中没有相应数据!" ,0)，不起作用，即满足条件"月份"," <> ",[%月份%]，也不显示没有数据的提示，请指教错在哪