Javascript：未捕获的TypeError：无法读取属性'rows'的null

Question

他是给我一个错误的JavaScript“未捕获的TypeError：无法读取null的属性'行'

var table = document.getElementById("table"),rIndex;

for(var i = 1; i < table.rows.length; i++)
{
    table.rows[i].onclick = function()
    {
        rIndex = this.rowIndex;
        console.log(rIndex);

        document.getElementById("id").value = this.cells[0].innerHTML;
        document.getElementById("nome").value = this.cells[1].innerHTML;
        document.getElementById("morada").value = this.cells[2].innerHTML;
        document.getElementById("localidade").value = this.cells[3].innerHTML;
        document.getElementById("telefone").value = this.cells[4].innerHTML;
        document.getElementById("codpostal").value = this.cells[5].innerHTML;
        document.getElementById("email").value = this.cells[6].innerHTML;
    };
}


// edit the row
function editRow()
{
    table.rows[rIndex].cells[0].innerHTML = document.getElementById("id").value;
    table.rows[rIndex].cells[1].innerHTML = document.getElementById("nome").value;
    table.rows[rIndex].cells[2].innerHTML = document.getElementById("morada").value;
    table.rows[rIndex].cells[3].innerHTML = document.getElementById("localidade").value;
    table.rows[rIndex].cells[4].innerHTML = document.getElementById("telefone").value;
    table.rows[rIndex].cells[5].innerHTML = document.getElementById("codpostal").value;
    table.rows[rIndex].cells[6].innerHTML = document.getElementById("email").value;
}

代码有什么问题？