I am trying to simply check if I have an empty input text box but I get this error when I run this in Chrome:
Uncaught TypeError: Cannot read property 'length' of undefined.
Here is how I go about doing it. I check for DOM readiness and then call the function:
function walkmydog() {
//when the user starts entering
if(document.getElementById('WallSearch').value.length == 0) {
alert("nothing");
}
}
if (document.addEventListener) {
document.addEventListener("DOMContentLoaded", walkmydog, false);
}
This question is related to
javascript
dom
dom-events
perhaps, you can first determine if the DOM does really exists,
function walkmydog() {
//when the user starts entering
var dom = document.getElementById('WallSearch');
if(dom == null){
alert('sorry, WallSearch DOM cannot be found');
return false;
}
if(dom.value.length == 0){
alert("nothing");
}
}
if (document.addEventListener){
document.addEventListener("DOMContentLoaded", walkmydog, false);
}
Source: Stackoverflow.com