Javascript Performance on mac?

[rokosz]

everything is aok on an MS-platform IE6

But on a MAC osX/IE4Mac the code below runs slower, with every iteration.
ie the first alert appears immediately, the next iteration takes maybe 1 sec, the next 3 secs, the next 8 secs, . By the time you're at the 30th or so -- its taking well over a minute. And it appears to freeze somewhere around the 40th.
Table is 25row x 3cell. alerts appear for 2nd & 3rd cell each row.

Does anybody know anything on a mac that must be "set"?

The alerts normally aren't there -- they were put in for analysis.
thank you folks. Bryan

Code:
function UnSelect() // clicked btnAdd in top
{var x,y
// deselect rows in browse table
for (y=0; y<window.outertable.rows.length ; y++)
{
for (x=1; x<window.outertable.rows(y).cells.length ; x++)
{ window.outertable.rows(y).cells(x).bgColor="#b14587"
strSource = window.outertable.rows(y).cells(x).innerHTML
alert(strSource)
window.outertable.rows(y).cells(x).innerHTML=strSource.substr(0,strSource.indexOf("face",1)-1) + " color=black " +strSource.substr(strSource.indexOf("face",1))
}
if (window.outertable.rows.length == 1)
{window.document.forms("frmReDisplay").TheSelection.checked=false
window.document.forms("frmReDisplay").TheSelection.disabled=true
}
else
{window.document.forms("frmReDisplay").TheSelection[y].checked=false
window.document.forms("frmReDisplay").TheSelection[y].disabled=true
}
}
window.document.forms("frmReDisplay").thePrevious.value = ""
window.document.forms("frmReDisplay").theCurrent.value = ""
}