Checking textbox is empty or not

[ravipatil]

hi

i am adding two numbers in C#.net & i want to check wheather first textbox is empty or not. if empty, then it must display "enter the first number" otherwise value is stored in first textbox1. Similarly for second textbox. and the sum of two numbers is stored third textbox.

thank you,

[anaphaxeon]

private int Number1 = 0;
private int Number2 = 0;


protected internal void AddNumbers()
{
ValidateForm();
this.TextBox3.T ext = Convert.ToStrin g(Number1 + Number2);
}
protected internal void ValidateForm()
{
try
{
Number1 = Convert.ToInt32 (this.TextBox1. Text);
}
catch
{
MessageBox.Show ("Please enter a valid number 1!");
this.TextBox1.F ocus();
this.TextBox1.S electAll();
}
try
{
Number2 = Convert.ToInt32 (this.TextBox2. Text);
}
catch
{
MessageBox.Show ("Please enter a valid number 2!");
this.TextBox2.F ocus();
this.TextBox2.S electAll();
}
}