I need to parse a element from a XML file:

<a>
<b>45</b>
<c>67</c>
</a>

<a>
<b>98</b>
<c>89</c>
</a>

So I try to read and put in a html element the first value of b with the next code:


Code:
document.getElementById("apDiv3").innerHTML=xmlDoc.getElementsByTagName("b")[0].data;

or

document.getElementById("apDiv3").innerHTML=xmlDoc.getElementsByTagName("b")[0].value;
and I get a undefined message.Where is the problem?