Updating local ColdFusion variable in Ajax - coldfusion-11

Question

I have been trying to perform a simple task (in ASP) for a coldfusion page. I have a local variable "pt.PreCaution" that I need updated. I have tried the following code with no success.
<cfset pt.PreCaution = "">
<label>
Patient Precaution:
</label>
<br>
<cfselect name="lstPreCaution" multiple="yes"
query="GetPreCaution"
value="IsoTypeID"
display="IsoTypeName"
size="8"
required="yes"
width="100"
height="25"
label="Precaution: "
onclick="PreCautionSelected(this)"
>
</cfselect>
function PreCautionSelected(val){
var result ="";
var frm=eval('document.next');
for(i = 0 ; i < val.children.length; i++)
{
if(val.children[i].selected){
if(result.length < 1)
{
result = val.children[i].value;
}
else
{
result = result + "," + val.children[i].value;
}
}
}
$.ajax({
type: "POST",
url: "details.cfm",
data: { "#pt.PreCaution#" : result}
}).done(function(){alert(result)})
}
I modified the ajax call as follows:
function PreCautionSelected(val){
var result ="";
var frm=eval('document.next');
for(i = 0 ; i < val.children.length; i++)
{
if(val.children[i].selected){
if(result.length < 1)
{
result = val.children[i].value;
}
else
{
result = result + "," + val.children[i].value;
}
}
}
$.ajax({
type: "POST",
url: "FileUpdater.cfc?method=setPrecautionType",
data: { lstPrecaution : result}
}).done(function(){})
}
<cfcomponent>
<cffunction name="setPrecautionType" access="remote" returntype="Any" >
<cfargument name="lstPrecaution" type="any" required="true" >
<cfset session.lstPreCaution = #arguments.lstPrecaution#>
<cfreturn />
</cffunction>
</cfcomponent>
I added the following CFC file. This file updates the session variables.
CFC File

Answer 1

Thanks for the input. The Ajax function is getting called and the complete data is being extracted. The only problem is the ColdFusion variable is not getting updated on the server side.
I fixed this problem by written the data to the session data. The problem is the old CF5 frame work that the program is written in.

Answer 2

You have only one mistake.select box not have onclick functionality so you have onchange function means working fine