if(ViewState["doSearch"]!=null) VB写法,该怎么处理

if(ViewState["doSearch"]!=null) VB写法
if(ViewState[ "doSearch "]!=null)   VB写法

[解决办法]
if not viewstate( "dosearch ") is nothing then
[解决办法]
If Not viewstate( "dosearch ") = Nothing Then