jquery - How can I hook into a true "OnChanged" event for an HTML Textbox (Input type Text)? -

i have following jquery, intent of replacing alert custom validation code has been entered in textbox:

$(document).on("change", '[id$=txtbxssnoritin]', function () {     alert('the textbox change event occurred'); }); 

however, event fires/the alert seen when "textbox" loses focus. entering value not invoke event; leaving control/element fires event.

should using event (other "change") or how can capture each change of content?

i don't want let user type in "warble p. mcgokle" , then, after tab out or click elsewhere, tell him/her/it value entered invalid. that's surefire way mugshot plastered onto center of company dartboard.

update

in jsfiddle, tymejv's script did work me; actually, changed to:

$(document).on("input", "textarea", function() {     alert('you entered ' + this.value); }); 

...but doesn't work me (in project/webpart):

$(document).on("input", '[id$=txtbxssnoritin]', function () {     alert('the textbox input event occurred'); }); 

(i see no alert while entering vals text element)

for context/full disclosure, here entire jquery (at end of *.ascs file):

<script type="text/javascript"> $(document).ready(function () {     console.log('the ready function has been reached'); /* "sanity check" can verified jquery script   running/ran */ });  /* when "employee" checkbox changes state, set txtbxssnoritin accordingly */ $(document).on("change", '[id$=ckbxemp]', function () {     var ssnmaxlen = 4;     var itinmaxlen = 12;     var ssntextboxwidth = 40;     var itintextboxwidth = 100;     var ckd = this.checked;     var $input = $('[id$=txtbxssnoritin]');     var $lbl = $('[id$=lblssnoritin]');      if (ckd) $input.data("oldvalue", $input.val()); // remember current value      $input.prop("maxlength", ckd ? ssnmaxlen : itinmaxlen).css({         background: ckd ? 'yellow' : 'lightgreen',         width: ckd ? ssntextboxwidth : itintextboxwidth     }).val(function (i, v) {         /* if checked, trim textbox contents ssnmaxlen characters */         return ckd && v.length > ssnmaxlen ? v.slice(0, ssnmaxlen) : $input.data("oldvalue");     });      $lbl.text(ckd ? "ssn - last 4 digits" : "itin");     /* sets focus end of textbox (multiplication 2 because characters counted two) */     var strlength = $input.val().length * 2;     $input.focus();     $input[0].setselectionrange(strlength, strlength); });  $(document).on("input", '[id$=txtbxssnoritin]', function () {     alert('the textbox input event occurred'); }); </script> 

changing event "input" "keyup" works fine, though, combination of tymejv's script , various suggestions comments worked wonders. change answer "keyup" , i'll mark correctamundo.

you can use input event fires whenever input modified (via paste, key stroke, etc)

$(document).on("input", '[id$=txtbxssnoritin]', function () { 

demo: http://jsfiddle.net/u9a9fvdo/