Detect Capital Letters Using Regular Expression

Hi all,

i'm using the code below to detect number in string but i also want to detect capital letter in string what is the regular expression for that...?

I've google and tried  many but no luck so far. Need help from expert here. Thanks.  

If isAllLetters = Regex.IsMatch(StringSetCheck, "^[a-zA-Z]+$") Then

Response.Write("Number Detected")

Else
Response.Write("All String")
End If