function addFile(){
var newrow = document.all["t1"].insertRow();
var newcell = newrow.insertCell();
newcell.innerHTML='<input name="file" contentEditable"=false" type="file" size=30>';
var newcell = newrow.insertCell();
newcell.innerHTML='<input type="submit" onclick="deleteRows(this.parentElement.parentElement.rowIndex )" value="ɾ³ý">';
}
function deleteRows(indexs){
document.all["t1"].deleteRow(indexs);
}