<input type=button value="Add" onclick='additem("tb")'> 
<table id="tb"></table> 
<script language="javascript"> 
function additem(id){ 
    var row,cell,str; 
    row = eval("document.all["+'"'+id+'"'+"]").insertRow(); 
    if(row != null ){ 
        cell = row.insertCell(); 
        str="<input type="+'"'+"file"+'"'+" name="+'"'+"addfile"+'"'+"><input type="+'"'+"button"+'"'+" value="+'"'+"delete"+'"'+" onclick='deleteitem(this,"+'"'+"tb"+'"'+");'>" 
        cell.innerHTML=str; 
    } 
} 
function deleteitem(obj,id){ 
    var rowNum,curRow; 
    curRow = obj.parentNode.parentNode; 
    rowNum = eval("document.all."+id).rows.length - 1; 
    eval("document.all["+'"'+id+'"'+"]").deleteRow(curRow.rowIndex); 
} 
</script>