How to combine similar JavaScript methods to one - asp.net

Question

I have an ASP.NET code-behind page linking several checkboxes to JavaScript methods. I want to make only one JavaScript method to handle them all since they are the same logic, how would I do this?
Code behind page load:
checkBoxShowPrices.Attributes.Add("onclick", "return checkBoxShowPrices_click(event);");
checkBoxShowInventory.Attributes.Add("onclick", "return checkBoxShowInventory_click(event);");
ASPX page JavaScript; obviously they all do the same thing for their assigned checkbox, but I'm thinking this can be reduced to one method:
function checkBoxShowPrices_click(e) {
if (_hasChanged) {
confirm(
'All changes will be lost. Do you wish to continue?',
function(arg) {
if (arg.toUpperCase() == 'YES') {
var checkBox = document.getElementById('<%=checkBoxShowPrices.UniqueID%
>');
checkBox.checked = !checkBox.checked;
eval("<%=base.GetPostBackEventReference(checkBoxShowPrices)%>");
_hasChanged = false;
}
});
return false;
} else {
eval("<%=base.GetPostBackEventReference(checkBoxShowPrices)%>");
}
}
function checkBoxShowInventory_click(e) {
if (_hasChanged) {
confirm(
'All changes will be lost. Do you wish to continue?',
function(arg) {
if (arg.toUpperCase() == 'YES') {
var checkBox = document.getElementById('<%
=checkBoxShowInventory.UniqueID%>');
checkBox.checked = !checkBox.checked;
eval("<%=base.GetPostBackEventReference(checkBoxShowInventory)%>");
_hasChanged = false;
}
});
return false;
} else {
eval("<%=base.GetPostBackEventReference(checkBoxShowInventory)%>");
}
}

Answer 1

Add to the event the checkbox that is raising it:
checkBoxShoPrices.Attributes.Add("onclick", "return checkBox_click(this, event);");
Afterwards in the function you declare it like this:
function checkBoxShowPrices_click(checkbox, e){ ...}
and you have in checkbox the instance you need

Answer 2

You can always write a function that returns a function:
function genF(x, y) {
return function(z) { return x+y*z; };
};
var f1 = genF(1,2);
var f2 = genF(2,3);
f1(5);
f2(5);
That might help in your case, I think. (Your code-paste is hard to read..)