Is there a way to protect against tampered QueryStrings or missing QueryString?

[test user]

I'm not really sure about this question but is there a way to protect against tampered/missing QueryStrings in ASP.NET?Example: I have this URL\[code\]http://localhost:56842/TCKT/Configs.aspx?type=view\[/code\]From Code Behind I'm getting the value like below:\[code\]Request.QueryString["type"];\[/code\]I know how to protect against missing values but I need to find out if there is a way to protect against missing QueryString meaning\[code\]?type=\[/code\]Is missing all together. I have seen people doing\[code\]Request.QueryString["type"].IsEmpty()\[/code\]But is not working for me and I'm not really sure if this is possible. Any help you could provide will be really appreciated.