在ajax td替换后，表单缺少提交的元素

I have a school district drop down with an onchange event tied to it. When it changes, then I do an ajax call to get a list of schools that are in that district. The html on the ajax page has checkboxes for each school so someone could be assigned to multiple schools under a single district. The ajax works fine and I modify the html of a td element with a specific id and the school names and their checkboxes appear correctly. I check a few of them and then submit the form, but to my dismay none of the input tags (checkboxes) that I added with the ajax come across in the form. I've checked some of them so the form field shouldn't come across empty in the submit.I have a school district drop down with an onch