Fetch data in second textbox against matching column by typing in first textbox using PHP and Jquery

I have sample table:

From	To	Grade
0	49	F
50	69	D
70	79	C
80	89	B
90	100	A

I have two textboxes Marks and Grades. When I type 50 in first textbox then second textbox should be populated with “D” grade.
How to do it with PHP and jquery?