I have file with jspx extension i write javascript like
function isNumber(inputId){
var value = document.getElementById(\'mainForm:\'+ inputId)
As explained by Matt Handy, you could not use the < or > sign in your JSPX, as this is a XML format. You have three solutions regarding your problem:
< or >. to hold your JavaScript code in your page..js file, and load it in your JSPX page.