jquery 获取jsp页面的id解决方法

<%@ include file="/COM_JSP/DIV/SG03_edit_youxiaoqi.lbi"%>	

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<script language="javascript" src="/SYS_JS/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript" src="/COM_JS/SG03_edit_youxiaoqi.js"></script>
<link href="/css/pub.css" rel="stylesheet" type="text/css" />
  <div id="edit_youxiaoqi" align="center" class="cataDiv">
   <div class="cataDivBtn">
    <a href="JavaScript:;" class="style1" onClick="_close_form('edit_youxiaoqi');">[关闭]</a>
   </div>
   <form name="form_edit_youxiaoqi" id="form_edit_youxiaoqi" method="post" action="../servlet/CustManager">
    <%@ include file="../../COM_JSP/LIB/comDiv.lbi"%>
    <table width="360" height="200" border="0" cellpadding="0" cellspacing="0" style="border: 1 solid #e7e3e7; border-collapse: collapse;">
   <tr>

				<th class="paddingT15">会员名称：</th>
			  <td class="paddingT15 wordSpacing5"><input name="C_CUST_NAME" type="text" id="C_CUST_NAME"  maxlength="20"  class="customTextInput" disabled>
		       &nbsp;<font color="#FF0000">*</font></td>
		    </tr>
			 <tr>

				<th class="paddingT15">会员开始时间11：</th>
			  <td class="paddingT15 wordSpacing5"><input name="D_CUST_SDATE" title="会员开始时间" attr="M" type="text" id="D_CUST_SDATE"  maxlength="20"  class="customTextInput"   style='enabled:false' onFocus=setday(this)  >
		       &nbsp;<font color="#FF0000">*</font><span id="D_CUST_SDATETip"></span></td>
		    </tr>
           <tr>
				<th class="paddingT15">会员结束时间：</th>
			  <td class="paddingT15 wordSpacing5"><input name="D_CUST_EDATE" title="会员结束时间" attr="M" type="text" id="D_CUST_EDATE"  maxlength="20"  class="customTextInput"    style='enabled:false' onFocus=setday(this)  >
		      &nbsp;<font color="#FF0000">*</font></td>
           </tr>         
       <tr>
      <td align="right"></td>
      <td>
       <input type='button' value="确定" onClick="_div_submit('edit_youxiaoqi')" class="buttomBgBlue">
       <input type='button' value="关闭" onClick="_close_form('edit_youxiaoqi');" class="buttomBgYellow">
      </td>
     </tr>
    </table>
   </form>
  </div>

$(function(){