function create_table(id){
var table = document.getElementById(id);
var rowCount = table.rows.length;
var row = table.insertRow(rowCount); 

var cell0 = row.insertCell(0);  
    var element1 = document.createElement("input");  
    element1.style.backgroundColor = "#DDDDDD";


    element1.setAttribute("type","text");
    element1.setAttribute("size","1");
    element1.setAttribute("name",seq);
    element1.setAttribute("id",seq);
    
    element1.setAttribute("value",val_sq );

    element1.setAttribute("readOnly","true");

    cell1.appendChild(element1);
}

If I call this function it shows TypeError: insertRow is not a function. I tried to get some answers from search engine.But no use. Please help me to find out