How about:
function deleteRow(rowid)
{
var row = document.getElementById(rowid);
row.parentNode.removeChild(row);
}
And, if that fails, this should really work:
function deleteRow(rowid)
{
var row = document.getElementById(rowid);
var table = row.parentNode;
while ( table && table.tagName != 'TABLE' )
table = table.parentNode;
if ( !table )
return;
table.deleteRow(row.rowIndex);
}