[fpc-pascal] Something like "Is a number"?

[Thomas Zastrow]

Hello,

I'm converting some strings with "strtoint" into integers. But sometimes 
the string can't be converted to a number. Is there a function which 
takes a string and tells me if it is possible or not to convert it into 
a number? Something like "IsANumber(string)"

Thank you very much!

Greetings,

Tom