getElementsByTagName() is a live HTMLCollection, so when you call c.remove(), the length of t becomes 1. You can circumvent this by caching t.length:

var tLen = t.length;
for (v i = 0; i < tLen; i++) {

It looks like you are trying to use .length to loop though an object, when .length only works on arrays.

getElementsByTagName() returns a object, not an array and Array.prototype.length only works on arrays.

I found a other post about getting an array of getElementsByTagName(): Link