How do I increase file submission size?

I tried to upload a file through the form and received an error that the file could not exceed 1024kb. I'm going to have files sent that will be much larger than that so how do I increase the allowed file size? 

You can change the allowed size for the file upload field by following this guide: http://www.jotform.com/help/33-Changing-the-Upload-Size-Limit. Let us know if you need more help on this.