Error messages when entering data

[ghjk]

I have two questions.
1.I have to enter values to database through php. When I enter incorrect value, it gives the error message. But i want to give it as a pop up message. how can i do that?

2. If I enter incorrect value and after the pop up message comes , I want to details that i entered earlier are exist. Otherwise I have to enter all these again. How can i do that?
Edit/Delete Message

[hsriat]

I have two questions.
1.I have to enter values to database through php. When I enter incorrect value, it gives the error message. But i want to give it as a pop up message. how can i do that?
2. If I enter incorrect value and after the pop up message comes , I want to details that i entered earlier are exist. Otherwise I have to enter all these again. How can i do that?
Edit/Delete Message

I guess you need JavaScript Validation