You can use local storage "jStorage" write a javascript which will be called onkey of textbox and store value on local storage and call it on page load. Just check on page load if local storage contains any value if yes then set the textbox with that value

Keeping values in textboxes permanently until changed by user in a sharepoint webpart
I ride about 17 miles each session. After the ride, the outside of my hips sore: only the parts near the outermost joints, most likely the tendon (although this is only a guess). My knees are fine, my ankles are fine, etc.

The only thing that might not fit perfectly for me is the seat height. I'd rather have a longer post so I can lift the seat up an inch or two. Do you think this might create the soreness in the area of the outer hips? 
