Microsoft® Visual Basic® Scripting Edition Log Function 
Language Reference Version 1

Returns the natural logarithm of a number.
Log(number)The number argument can be any valid numeric expression greater than 0.
The natural logarithm is the logarithm to the base e. The constant e is approximately 2.718282.You can calculate basen logarithms for any number x by dividing the natural logarithm of x by the natural logarithm of n as follows:
The following example illustrates a custom Function that calculates base10 logarithms:Logn(x) = Log(x) / Log(n)
Function Log10(X) Log10 = Log(X) / Log(10) End Function