Change colour of table cells depending on value

Question

I\'m using jQuery to edit the background-color of table cells. My code is as follows (the each cell has numbers in the format \"x/y\" so I mine them out at the star

Answer 1

Thanks Nunners, there were header values that broke the code. I've fixed it using the following if block:

if(vals[1] == undefined){
    return true;
} else{
    //change colour
}