Choose a value from a combo box based on a text box

[Slim Shamble]

Hi

I am new to Ms access. I have a form which is use to input student data for assessment report. i have a text box and a combo box namely total and status respectively. the status has its own text in it as Pass & fail. I want my combo box value to change to pass if value in total is > 45 and fail if value in total is < 45.

I hope is understood. Kind respond will be appreciated.

Seal D Deal.