i notice that every web server controls have a property runat='server', when i chenge the value of this property at design time, a warming will be shown like this:
this is a very good feature.
now i want use this feature into my custom control developed by my self.
my control like this:
i just want my control check the property Old not large than 130 and not less than 0 at design time , what can i do?
thank you very much.