Select() not working

[mickeymouse]

Why iis it that 'onload' perfectly selects the "01" in my 'mm' box and highlights it but 'myreset' only selects the box and does not highlight the '01'? i.e., the 'reset' does not work and yet my code is exactly the same as the 'onload'.

window.onload = function()
{var c = document.CorForm.mm;
c.select();}

function myreset()
{var c = document.CorForm.mm;
c.select();}

<input style=\"text-align: center\" name=\"mm\" size=\"1\" MaxLength=2 value=\"01\" onkeyup=\"mytab(mm,dd,2)\">

<input type=\"reset\" value=\"Reset\" onclick=\"myreset()\">

Thank you