Multiple Columns which need to be combined with some columns not having all the cells fill

Okay here is a doosy....At least for me. I have a spreadsheet with 10 columns which are for tags for products. Some columns are filled in for 10 products and some are not. For instance, product 1 has 7 tags while product 2 has only 2 tags and so on. Now what I am looking to do is combine all the tags for each product with a "," inbetween each one. The problem is if I just use a simple =A2&","&B2&","&C2 etc formula is that if there are only 2 tags then I get 8 ","s. I also tried it with an IF statement but by the time I was done nesting items I became cross eyed and said there has to be an easier way to do this.

I have create a spreadsheet with the data and the result that I typed into the "result" column.

Any help would be appreciated.

Thanks

Mike