Javascript traversal elements in table example code

For example:

 <table id=tb> <tr><th></th><th></th><th></th><th></th></th></tr> <tr><td></td><td></td><td></td><td></td></tr> <tr><td></td><td></td></tr></table>

And how to traverse assignments in JS?

Program code

 var count=0;for(i=0; i < document.getElementById("tb1").rows.length; i++){ for(j=0; j < document.getElementById("tb1").rows(i).cells.length; j++) { document.all.getElementById("tb1").rows(i).cells(j).innerText = count; count++; }}

I saw another way to use dom (but I didn't try it myself, I don't know why)

 <table id="mylist"><tr><td>A monk has water to drink. </td></tr><tr><td>The two monks carried water and drank it. </td></tr><tr><td>The three monks had no water to drink. </td></tr></table><script>var msg=””var mylist=document.getElementByIdx("mylist")for (i=0; i<mylist.childNodes.length; i++){var tr=mylist.childNodes[i];for(j=0;j<tr.childNodes[j].length; j++) {var td=tr.childNodes[j];msg+=td.innerText;}}alert(msg);</script>