Forcing List Form field to uppercase in Newform.aspx

I've been able to force list textboxes in newoform to uppercase by modifying the newforms.aspx source in SharePoint Designer- first removing the listform webpart and replacing it with a custom one, then changing the column in question to a textbox and then messing with the html tag or adding a javascript codeblock.  It works, but the form is then no longer updated when columns are changed and inserted in the list.

Any way to acheive this without all that and leaving the form alone, maybe by adding some javasript?

Thanks for any help or information!