I have following javascript to prevent user from entering invalid characters into a text field. It's working well in chrome but not in firefox. It's preventing the backspace key to be entered in the text field in firefox.
function onlyNumbers(evt) {
var theEvent = evt || window.event;
var key = theEvent.keyCode || theEvent.which;
key = String.fromCharCode( key );
var regex = /[0-9]|\./;
if( !regex.test(key) ) {
theEvent.returnValue = false;
if(theEvent.preventDefault) theEvent.preventDefault();
}
}
Can anyone please have a look and propose a fix for firefox to not prevent backspace key to act on a text field ?
Probably I guess, adding the regex for the backspace character would do the job here. Does anyone know, how to add the regex for matching the backspace
Also, the above code has supposed to interrupted with the Tab key behaviour, I am not able to jump to next fields in the form using Tab key.
see http://jsfiddle.net/8ZJZD/1/
var el=document.getElementById('cnfMobileNo');
el.onkeydown=function onlyNumbers(evt) {
var theEvent = evt || window.event;
var key = theEvent.keyCode || theEvent.which;
if(key===8){return;}
key = String.fromCharCode(key);
var regex = /[0-9]|\./;
if( !regex.test(key) ) {
theEvent.returnValue = false;
if(theEvent.preventDefault) theEvent.preventDefault();
}
}
Just use if(key===8){return;}
Edit:
If you want to exclude more keys, use
var el=document.getElementById('cnfMobileNo');
el.onkeydown=function onlyNumbers(evt) {
var theEvent = evt || window.event,
key = theEvent.keyCode || theEvent.which,
exclusions=[8,9]; /*Add exceptions here */
if(exclusions.indexOf(key)>-1){return;}
key = String.fromCharCode(key);
var regex = /[0-9]|\./;
if( !regex.test(key) ) {
theEvent.returnValue = false;
if(theEvent.preventDefault) theEvent.preventDefault();
}
}
See it here: http://jsfiddle.net/8ZJZD/2/
You can know the keyCode of each key using alert(key)
(before key = String.fromCharCode(key)).
You could also exclude