javascript动态创建table

function createTable(node) { 

table = document.createElement("table");
table.setAttribute('class', 'tablestyle');
var k = 1;

for (var i=1; i<4; i++) {

var row = document.createElement("tr"); 
row.id = i;

for (var j=1; j<4; j++) {

var cell = document.createElement("td"); 

cell.id = i + '_' + j;

cell.appendChild(document.createTextNode(k)); 

row.appendChild(cell);

k = k + 1;

}
table.appendChild(row);

}
node.appendChild(table);
}