<tr height="30px">
				<td class="labelNotBlank">是否使用第二</td>
				<td>
					<select name="dier" id="dier"  onchange="onchanged();">
						<c:if test="${obj.blockApp.twoMarginAmount == null }">
							<option value="0" selected="selected">否</option>
							<option value="1" >是</option>
						</c:if>
						<c:if test="${obj.blockApp.twoMarginAmount != null }">
							<option value="0" >否</option>
							<option value="1" selected="selected">是</option>
						</c:if>
					</select>
				</td>
			</tr>
            <tr height="30px" id="showMeg">
            
			</tr>	

<script type="text/javascript">
	function onchanged(){
  		var id = document.getElementById("dier").value;
  		//var showMsg = document.getElementById("showMeg");
  			if(id=='1'){
  	  			
  	  			$('#showMeg').html("<td class='labelNotBlank'>第二</td><td><input type='text' name='twoMarginAmount' id='twoMarginAmount' value='<fmt:formatNumber pattern='#.####'  value='${obj.blockApp.twoMarginAmount}'></fmt:formatNumber>' min='0.0001'  class='required number'  maxlength='20' /> <span>万</span></td>");
  	  		}else{
  	  			$('#showMeg').html("");
  	  		}
  	}
</script>

现在想要实现选否之后,将value='${obj.blockApp.twoMarginAmount}'传如数据库中的数据删除,该用什么方法,怎样添加代码?