How to check for capital letters using regular expressions in QTP?

I need to check the login page of a website using QTP. I have a list of usernames in the global datasheet. I need QTP to pass only those usernames which are in smaller case using the standard checkpoint. I used [a-开发者_如何学Pythonz]+ in the regular expression. But it is passing those usernames which are in uppercase also. How can i do it?

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negate uppercase in the whole string like this:

^[^A-Z]+$

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Here is what I use

^ and $ match the positions at the beginning and end of the string, which mean search the entire string for the specific patter.

[A-Z] Means a range of characters between A to Z in Uppercase; means the 1st Character of the string must be in Capital letter.

Thanks,

Rekha