结束日期不能大于开始日期
<input id="d4311" class="Wdate" type="text" onFocus="WdatePicker({maxDate:'#F{$dp.$D(\'d4312\')}'})"/>
<input id="d4312" class="Wdate" type="text" onFocus="WdatePicker({minDate:'#F{$dp.$D(\'d4311\')}'})"/>
<input id="d4311" class="Wdate" type="text" onFocus="WdatePicker({maxDate:'#F{$dp.$D(\'d4312\')}'})"/>
<input id="d4312" class="Wdate" type="text" onFocus="WdatePicker({minDate:'#F{$dp.$D(\'d4311\')}'})"/>