Custom JavaScript - Not working in chrome

I'm getting errors on the filter:

Uncaught TypeError: Cannot read property 'innerHTML' of undefined

What I'm doing wrong?

for (i=0;i<50;i++)
{
    e = document.getElementsByTagName("tr")[i];
    z = e.innerHTML;
}

• You don't know if you will have always 50 elements.
• You are using incorrectly innerHTML
• You are calling getElementsByTagName in every iteration

Solution:

var nodes = document.getElementsByTagName("tr").childNodes;
//Iterating through TR childs 
for(i=0; i<nodes.length; i++) {
    alert(nodes[i]);
}

Alternative: If you are not a Javascript expert, I recommend to use jQuery to manage the DOM elements, it's cross browser and very documented. For example, you could do something like this with jQuery instead the whole for loop:

$('tr > td:not(:contains("+filter_text+")')).hide();