Findtune.com is supposed to recognize and identify a melody based on the ups and downs, longs and shorts of a melody description. The challenge is how to input that description easily and accurately. There are currently two input techniques - "Play" and "Type".
If the input type is set to "Play" (the default) then you enter the description of the melody you have in mind by "playing" it on the keyboard, almost as if it were a piano keyboard. Using the middle row of keys, tap the rythm of the melody, moving to the right on the row as pitch goes up, and to the left as pitch goes down. So for "Happy Birthday to You" you might type: "hhjhjhgghgjhggjhgfdhhgfjhq". You have to provide the correct timing, but it doesn't matter how much you go up or down, only the relative position. The 'q' at the end terminates your input, and is only used to get the timing of the last interval.
Note that if you are unsure about the rythm, it is best to check the "Ignore Timing" box, in which case only the ups and downs of your input will be recorded.
Use the "Type" setting if you wish to go in and edit anything about the input you have given. In particular, note that any key (including the arrows) will modify the input in "Play" mode, so go to "Type" mode before hitting anything other than melody input.
The input algorithm is sufficiently sloppy that hitting two keys too quickly can cause erroneous input in the text box. You can either then switch to "Type" mode to correct it, or just hit "Clear Input" and start over (much easier).