adding a strap to a handbag?

i'm making a purse out of a section cut from the leg of an old pair of jeans. the top of the purse is the hem of the leg, and it folds over and buttons in front. the fabric's thick enough that it will give me difficulty should i try to machine-sew along the seam. because it's basically the lower leg portion, the sides are already stitched up, and because it folds over, sewing strips onto the front won't work either. what's the best way to add a shoulder strap? it's my hope to make it pretty sturdy, i tend to carry lead weights and heavy boulders around with me in my purse,just for the hell of it. will it be strong enough if i hand-stitch webbing, sturdy embroidered ribbon or a strip from an incle loom along the side?

 

*~well gosh that sounds like fun! i think i understand what your talking about! if you are worried about the denim being too thick ~ try getting some *DENIM* needles for your machine for a buck or two at the local sewing store ~ they really do work wonders on denim and thick cords. as for attatching the strap ~ you could do so at the back of the bag like when its all folded over and looking as it would when closed attatch the straps flat against either edge of the back of the bag. i DO hope that makes sense ~ you must put a closing button/snap/whatever at the front though because when you attatch the strap to the back the bag will slightly lean forwards with weight. hope that was clear enough to help darling!*~