asp.net中请求的问题

我在一个页面中 有这样一个脚本语言
var sURL =mapmake.aspx+"?axlrequest="+taxl;
其中taxl的值为下面格式 我在mapmake.aspx中 用 sAXLText=Request.QueryString["axlrequest"] 得不到值 ！！！！！怎么回事？
<?xml version="1.0" encoding="UTF-8"?>
<ARCXML version="1.1">
  <CONFIG>
    <ENVIRONMENT>
      <LOCALE country="CN" language="zh" variant="" />
      <UIFONT color="0,0,0" name="SansSerif" size="12" style="regular" />
      <SCREEN dpi="96" />
    </ENVIRONMENT>
    <MAP>
      <PROPERTIES>
<ENVELOPE minx="-178.21759836236586" miny="18.924781799316406" maxx="-66.96927103600244" maxy="71.40623535327121" name="Initial_Extent" />
<MAPUNITS units="decimal_degrees" />
      </PROPERTIES>
      <WORKSPACES>
<SHAPEWORKSPACE name="shp_ws-4" directory="D:\Program Files\ArcGIS\ArcIMS\Samples\NET_Link\BlueViewer\data" />
      </WORKSPACES>
      <LAYER type="featureclass" name="States" visible="true" id="0">
<DATASET name="States" type="polygon" workspace="shp_ws-4" />
<GROUPRENDERER>   
<SIMPLELABELRENDERER field="POP1990">
    <CHARTSYMBOL mode="pie" outline="255,255,255" shadow="0,0,0" minsize="10" maxsize="50" minvalue="1000000.0" maxvalue="7000000.0">
      <CHARTVALUE lookupfield="POP1990" color="255,0,0" />       
    </CHARTSYMBOL>
  </SIMPLELABELRENDERER>   
</GROUPRENDERER>
<GROUPRENDERER>   
<SIMPLELABELRENDERER field="POP1990">
    <CHARTSYMBOL mode="bar" outline="255,255,255" shadow="0,0,0" minsize="10" maxsize="50" minvalue="1000000.0" maxvalue="7000000.0">
      <CHARTVALUE lookupfield="POP1990" color="255,0,0" />       
    </CHARTSYMBOL>
  </SIMPLELABELRENDERER>
</GROUPRENDERER>
      </LAYER>
    </MAP>
  </CONFIG>
</ARCXML>