    function changeContent()  
    {  
    rn = window.prompt("Input the Row number(0,1,2)", "0");  
    cn = window.prompt("Input the Column number(0,1)","0");  
    content = window.prompt("Input the Cell content");    
    var x=document.getElementById('myTable').rows[parseInt(rn,10)].cells;  
    x[parseInt(cn,10)].innerHTML=content;  
    }  