when trying to use labels in loops... i get this in the console "SyntaxError: Undefined label"

when trying to use labels in loops... i get this in the console "SyntaxError: Undefined label"
but it works in codepen and jsbin

this is the code

```
var x = 0;
var z = 0;

myLoop:

while(true) {
document.write("Outer Loops" + x + "........
");
x++;

z = 1;
while(true){
document.write("Inner Loops" + z + "........
");
z++;
if (x === 10 && z === 10) {
break myLoop;
}
else if(z === 10) {
break;
}
}
}
```