Sys is undefined

[jxshunsheng]

<script language="javascript" type="text/javascript">

var prm = Sys.WebForms.PageRequestManager.getInstance();

function CancelAsyncPostBack() {

if (prm.get_isInAsyncPostBack()) {

prm.abortPostBack();

}
}
</script>

总是提示 Sys is undefined

高手帮帮忙啊

[yongyinmg]

你用ajax了吧
在web.config的system.web节点添加
<httpHandlers>
<remove verb="*" path="*.asmx"/>
<add verb="*" path="*.asmx" validate="false"

type="Microsoft.Web.Script.Services.ScriptHandlerFactory, Microsoft.Web.Extensions,

Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add verb="*" path="*_AppService.axd" validate="false"

type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions,

Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add verb="GET,HEAD" path="ScriptResource.axd"

type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0,

Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
</httpHandlers>
<httpModules>
<add name="ScriptModule" type="System.Web.Handlers.ScriptModule,

System.Web.Extensions, Version=1.0.61025.0, Culture=neutral,

PublicKeyToken=31bf3856ad364e35"/>
</httpModules>

另外，把scriptmanager标记放到紧跟form标记的后面

[caofan520]

Sys不是对象当然报错了

你要讲Sys.WebForms.PageRequestManager.getInstance()这是一个什么东东
怎么来的