简单的js变量传递问题，紧急求助！！！！！

问题：formHidden.Parameter_name     未定义。
js:
function   mySelect(formHidden,   i)
{

var   obj_Parameter_name   =   eval( "formHidden.Parameter_name "   +   i);
alert(obj_Parameter_name);


formHidden.Parameter_name.value   =   obj_Parameter_name.value;

  var   obj_Parameter_type   =   eval( "formHidden.Parameter_type "   +   i);
formHidden.Parameter_type.value   =   obj_Parameter_type.value;

var   obj_Parameter_desc=   eval( "formHidden.Parameter_desc "+i);
formHidden.Parameter_desc.value   =   obj_Parameter_desc.value;

var   obj_Data_type=   eval( "formHidden.Data_type "+i);
    formHidden.Data_type.value   =   obj_Data_type.value;

formHidden.opFlag.value= "query ";
formHidden.statusFlag.value= "selected ";
formHidden.detailQuery.value= "true ";
formHidden.checkParameterName.value=obj_Parameter_name.value;
formHidden.target= "_self ";
formHidden.submit();
}

JSP:    
中的form表单：
<form   name= "formHidden "   action= "/cerp/viewProSerInfo "   method= "Post ">
<input   type= "hidden "   name= "currentPage "   value= " <%=currentPage%> ">
<input   type= "hidden "   name= "pageCount "   value= " <%=pageCount%> ">
<input   type= "hidden "   name= "opFlag "   value= "query ">
<input   type= "hidden "   name= "detailCurrentPage1 "   value= " <%=detailCurrentPage1%> ">
<input   type= "hidden "   name= "detailPageCount1 "   value= " <%=detailPageCount1%> ">
<input   type= "hidden "   name= "detailQuery "   value= " <%=detailQuery%> ">
<input   type= "hidden "   name= "checkID "   value= " <%=checkID%> ">
<input   type= "hidden "   name= "checkVersion "   value= " <%=checkVersion%> ">
<input   type= "hidden "   name= "checkServiceName "   value= " <%=checkServiceName%> ">
<input   type= "hidden "   name= "checkParameterName "   value= " <%=checkParameterName%> ">
<input   type= "hidden "   name= "showFlag "   value= " <%=showFlag%> "   >
<input   type= "hidden "   name= "statusFlag "   value= " <%=statusFlag%> "   >
<input   type= "hidden "   name= "Parameter_name "   >
<input   type= "hidden "   name= "Parameter_type "   >
<input   type= "hidden "   name= "Parameter_desc "   >
    <input   type= "hidden "   name= "Data_type "   >
<input   type= "hidden "   name= "card_Parameter_name "   >
<input   type= "hidden "   name= "card_Parameter_type "   >
<