sir, i'm sorry for having lack of knowledge in coding.

i need to convert the textbox field to numeric field.i used the code like this

Convert.ToInt32 (textBox1.Text) ; this code is used to convert string to integer.

Now i need to print an error message by messagebox like "Please enter the Number"..

the following codes i made having no sense i think..

if(String.Equal s(textBox1.Text )...

Actually i need a help that i created a program in visual studio 2008-windows form application. But there is a logical error that i can't run multiple radiobutton. i placed 18 radiobutton in groupbox1 and other five radiobutton placed in groupbox2. if i select radiobutton1 from groupbox1 i need to get enable groupbox2 and some radiobutons need to be enabled. like this way other radiobuttons from groupbox1 will handle the groupbox2 contents.
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