js代码收藏三：My97DatePicker日期选择的限制

<tr bgcolor="#FFFFFF">
<td nowrap colspan="1"> <strong>免评有效期：</strong></td>
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从   <input type="text" id="operate_stime" class="Wdate" style="background-color: #FFF;" name="operate_stime" <c:if test="${freeEvalAccount.state eq states[1]  or freeEvalAccount.state eq states[2]}" >value="<fmt:formatDate value="${freeEvalAccount.start_period}" pattern="yyyy-MM-dd"/>"</c:if>  onfocus="WdatePicker({dateFmt:'yyyy-MM-dd',maxDate:'#F{$dp.$D(\'operate_etime\')}',onpicked:function(){operate_etime.focus();}})"  onchange="change();" <c:if test="${freeEvalAccount.state eq states[2]}">disabled</c:if>/>
<font color="#FF0000"> *</font>至
<input type="text" id="operate_etime" class="Wdate" style="background-color: #FFF;" name="operate_etime" <c:if test="${freeEvalAccount.state eq states[1] or freeEvalAccount.state eq states[2]}" > value="<fmt:formatDate value="${freeEvalAccount.end_period}" pattern="yyyy-MM-dd"/>"</c:if>  onfocus="var date=getSysdate();WdatePicker({dateFmt:'yyyy-MM-dd',minDate:date})"  <c:if test="${freeEvalAccount.state eq states[2]}">disabled</c:if>/>
<font color="#FF0000"> *</font>
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function getSysdate(){
//  结束时间大于开始时间并且大于系统时间
var operate_stime = document.getElementById("operate_stime").value;
var now = new Date();
var month = now.getMonth()+1 > 9?now.getMonth()+1:'0'+(now.getMonth()+1);
var day = now.getDate()+1 > 9?now.getDate():'0'+now.getDate();
var str = now.getYear()+"-"+month+"-"+day;
return operate_stime>str?operate_stime:str;
}