for(var i=0; i<document.data1.cb.length; i++){
if(document.data1.cb[i].checked)
{
document.getElementById('res').deleteRow(document.data1.cb[i].value);
}
}
document.data1.cb.length this value will be different when u delete one row
say
your total length is 10
now if u delete 1st row then length will be 9 and index value will be 1
so for loop will not be executing 10 times
for(var i=0; i<document.data1.cb.length
; i++){
if(document.data1.cb[i].checked)
{
document.getElementById('res').deleteRow(document.data1.cb[i].value);
i=0;
}
}