global variables not recognised in other frames.

[Guest]

i have a .js file with all the variables that are used in one frame but i
can not use these in other frames even though their are global.

i have my second frame that needs the variables that looks like this. but
does not print when the variable (_numberofitems) is more than 0 (zero) this
variable is set via another frame, which sets the variables as global.

<script language="JavaScript">
if (_item = 0) {
document.write("itemname");
document.write(_numberofitems);
document.write(_costofitem);
document.write("= £");
document.write(_numberitems*_costofitem);
document.write("p");
}

</script>

please advise how i can fix this so it displays like this.
itemname
numberofitems = £ _numberofitems*_costofitem


thank you