implementing table using javascript

hi all,
i am creating an html editor ,i want to include table and table alterations.how do i implement a table using javascript,please suggest

i have written something like this
function doCell()
{
var rowno=prompt('please enter the no of rows','');
var colno=prompt('please enter the no of cols','');
iView.document.write(rowno);
iView.document.write("<table width=100% border=1>");
if(rowno!=''||colno!='')
for( i=1;i<=rowno;i++)
{ iView.document.write("<tr>");
for( j=1;j<=colno;j++)
{
iView.document.write("<td width=25% height=50%>");
iView.document.write("</td>");
}
iView.document.write("</tr>");
}

iView.document.write("</table>");
}

this gets implemented on the click of a table image.
how do i implement alterations to the table please suggest

Regards