copy column headings of cells with missing data into a single cell

Hi, i want to be able to take the text column headings from a row and compile them into one cell based on the contents of the cells in the row.

that does not make alot of sence so i have added an attachment.

This..
=IF(B2="n",$B$1&", ","")&IF(C2="n",$C$1&", ","")&IF(D2="n",$D$1&", ","")&IF(E2="n",$E$1&", ","")&IF(F2="n",$F$1&", ","")&IF(G2="n",$G$1&", ","")&IF(H2="n",$H$1&", ","")&IF(I2="n",$I$1,"")
is the solution i have so far but i would like something more elegant which would work for up to 30-40 columns without having to have 30-40 if statements.

any ideas

Thanks
Mat