I got tired of having to press tab each time when I enter my SS number in the Unemployment Insurance Benefits Online website so I made this GreaseMonkey script. I'm not so good in JS but it gets the job done. I'm pretty sure it can be written better.

JavaScript:
  1.  
  2. // ==UserScript==
  3. // @name           Unemployment Insurance Benefits Online by JayBachatero
  4. // @namespace      http://www.jaybachatero.com
  5. // @description    Go to next field when entering ssn.
  6. // @include        https://ui.labor.state.ny.us/UBC/home.do
  7. // @version        1.0
  8. // ==/UserScript==
  9.  
  10. // The name of the fields we are going to look for.
  11. var ssn_fields = new Array(
  12.         ['ILoginForm.SSN1_KEY', 3],
  13.         ['ILoginForm.SSN2_KEY', 2],
  14.         ['ILoginForm.SSN3_KEY', 4]
  15. );
  16. // Current field.
  17. var current_field = 0;
  18.  
  19. function goToNextField()
  20. {
  21.         // Stop right there.
  22.         if (current_field> 2)
  23.                 return;
  24.  
  25.         // Field properties.
  26.         var id = ssn_fields[current_field][0];
  27.         var field_properties = document.getElementById(id);
  28.         // Current value.
  29.         var current_value = field_properties.value.length;
  30.         // Check the current field.
  31.         if (current_value == ssn_fields[current_field][1])
  32.         {
  33.                 // Increase the current_field
  34.                 current_field = current_field>= 2 ? 2 : current_field + 1;
  35.                 // Move to the next field.
  36.                 document.getElementById(ssn_fields[current_field][0]).focus();
  37.         }
  38.  
  39.         // Only if the current field is not the last one.
  40.         setTimeout(goToNextField, 500);
  41. }
  42.  
  43. // Start it.
  44. setTimeout(goToNextField, 1000);