Is there a standard way to validate data entry for numeric decimal data? Numbers like 5.5 or 6.25? I only need to check that it is a number.

The data is enterred in a text box with a control source value set to 0.(texbox.controlsource = mvar, mvar = 0) If I use no input mask,control jumps to the next control as soon as the decimal point is enterred. If I use an input mask of 99.99, an entry of 6.25 results in a value of 60.25. If I change the data type to string, I need a way to trap all non numeric or decimal point data.