真诚请问一个cf修改xml的有关问题

<?xml version="1.0" encoding="utf-8"?>
  <root Name="root">
       <child Name="child1" Expression="1000&lt;1&gt;1001&lt;11&gt;/>
       <child Name="child2" Expression="1000&lt;2&gt;1001&lt;22&gt;/>
  </root>

<cfset ThisPath="#getDirectoryFromPath(getTemplatePath())#">
<cffile action="read" charset="utf-8" 
file="#ThisPath#1.xml" variable="myXMLFile">
<cfset XMLDoc=XMLParse(myXMLFile)>
<cfset item=XMLDoc.XMLroot.XMLChildren[1]>
   <form action="edittest.cfm" method="post" >
      <input name="sExpression" value="<cfoutput>#item.XMLAttributes["Expression"]#</cfoutput>"/>
      <input type="submit" name="Submit" value="修改" />
    </form>

<cfset ThisPath="#getDirectoryFromPath(getTemplatePath())#">
<cffile action="read" charset="utf-8" 
file="#ThisPath#1.xml" variable="myXMLFile">
<cfset XMLDoc=XMLParse(myXMLFile)>
<cfscript>
XMLDoc.XMLroot.XMLChildren[1].XMLAttributes["Expression"]= "#form.sExpression#";
</cfscript>
<cffile action="write" addnewline="no" 
charset="utf-8" file="#1.xml" 
output="#toString(XMLDoc)#">
<cfoutput>成功修改xml文件!</cfoutput>

<cfset form.sExpression = replace(form.sExpression, ">","&gt;","all")>