Im trying to apply conditional formatting to a cell depending upon what is in another cell eg.

A2 has a drop down box for either either yes or no

B2 If A2 = "Yes" or has no selection then I want to grey this cell out if "No" then i want the cell to be white

C2 If A2 = "Yes" or has no selection then I want to grey this cell out if "No" then i want the cell to be white and have the text "You must complete the required information"

I have tried various ways of entering formula's in conditional formatting but so far unsucessfully. For the text in c2 i can use an IF statement