IsNumeric in C#

I can still remember when I used to use the Visual Basic function (was it a function?)

IsNumeric(...)

in which I was able to know if an entry data was or not a numeric value.
Well, we are not going to find such as kind of function in any library in C# (at least until framework 4), so I wrote a quick version in C#.
Here is the utility function:

        private bool IsNumeric(string strEntry) 
        { 
            if (strEntry == null) 
            { 
                return false; 
            } 
            else 
            { 
                Regex obj = new Regex("[^0-9]"); 
                return !obj.IsMatch(strEntry) && (strEntry != string.Empty); 
            } 
        } 

Don't forget to import the following library:

using System.Text.RegularExpressions;