Regex to allow entry of 0 - 9, decimal point, negative sign only

Regex to allow entry of 0 - 9, decimal point, negative sign only

Hi. As the title say's i need regex to handle that one. I need only "dot" and "negative sign" only when i set values in my textbox.

Some examples of values are:

53.525356 or 5.353656

or if negative:

-22.1234 or 2.1234

Thanks