<!DOCTYPE html>
<html>
<head>
<style>
table, td {
border: 1px solid black;
}
</style>
</head>
<body>
<p>Click the button to alert the innerHTML of the first tr element (index 0) in the table.</p>
<table id="myTable">
<tr>
<td>Row1 cell1</td>
<td>Row1 cell2</td>
</tr>
<tr>
<td>Row2 cell1</td>
<td>Row2 cell2</td>
</tr>
<tr>
<td>Row3 cell1</td>
<td>Row3 cell2</td>
</tr>
</table>
<br>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction() {
alert(document.getElementById("myTable").rows[0].innerHTML);
}
</script>
</body>
</html>