JSP not showing the integer value

Hi,
I am new to this forum and hoping some will help me with this question.

I am unable to display the value that is passed by jsp to the controller.

This is the jsp code
Var num = 10
var sel = document.getElementById("selection");
sel.options.length=0
var opt=0;
for (var a = 1; a < parseInt(num)+1; a++) {
sel.options.add( new Option(a,a) );
opt++;
}
This is my domain code
private String selection;
public void setmySelection(String selection)
{this. selection = selection;
}
public String getmySelection() {
return selection; }
getmySelection() only returns a null values.
Can someone help?
Thanks you.