asp.net mvc 4 - Textchanged event in mvc for a Textbox -

i beginer in mvc.i working on application need change value of textbox after enter value in , press tab.for example when enter 1 in textbox , press tab should display +1 ie need concatinate + sign text enter.so trying raise textchanged event textbox.how can it.when googled found can done using javascript.but dont know how that,pls give me suggessions.

code:

 @html.textboxfor(m => m.text)--textbox 

you use jquery , subscribe blur event triggered when input field looses focus:

$(function() {     $('#id_of_your_textbox').blur(function() {         var value = $(this).val();         var newvalue = value + '1';         $(this).val(newvalue);     }); }); 

if don't want use javascript framework such jquery achieve same plain javascript:

window.onload = function() {     document.getelementbyid('id_of_your_textbox').onblur = function() {         var value = this.value;         var newvalue = value + '1';         this.value = newvalue;     }; }; 

note: add string value 1 existing text. if wanted perform integer addition need parse current value first. use parseint or parsefloat methods (depending on data type) that:

var value = parseint($(this).val()); if (!isnan(value)) {     var newvalue = value + 1;     $(this).val(newvalue); } else {     alert('you have entered invalid integer value'); } 

and here's how assign deterministic id text field use in javascript selectors:

@html.textboxfor(m => m.text, new { id = "id_of_your_textbox" })