What I need is for a textbox to be disabled and enabled until I write 4 numbers in a previous textbox. The textboxes are asp: Textbox. The truth is I have not tried it because I do not know how, and it occurs to me that it could be with jquery or from the behind code c #. Thanks for reading.
For this I would use the keyup
eventDocumentation jQuery keyup () Method
I hope it serves you
$("#txt1").keyup(function() {
var _this = $(this);
if (_this.val().length >= 4) {
$('#txt2').removeAttr("disabled");
}else{
$('#txt2').attr("disabled", "disabled");
}
});input[disabled] {
background-color: #eee;
cursor: not-allowed;
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="textbox" id="txt1" placeholder="Escribe ...">
<input type="textbox" id="txt2" disabled>