You need to set the max character limit for the first textbox. For example, if you set the limit to the 5 chars then on the
textChanged
event of the first textbox check the char length of it, and if it is equal to 5 then set focus to the second textbox and continue typing your text.
I don't know on what technology you're working on i.e Forms App or ASP .NET, that's why I am not able to code it. Below is the Forms App code,
private void textBox1_TextChanged(object sender, EventArgs e)
{
if (textBox1.TextLength == 5)
{
textBox2.Focus();
}
}
Hope it would help you. ;)
-KR