How to write js for Erpnext and where i can placed on that app

Hiii frndzz…
i want to know something about Erpnext… Because i am fresher for this field. So please help me how to write script code for DocType and other client side coding and where i can write that code.


You can check here

Thank you for your best reply… Already i have working on that same way but that coding not supported or run. So please help me…


You can share code here. I will check

Actualy my concept is avoiding duplicate IP value in a child table…
my code like… given below…

frappe.ui.form.on(“STORE”, “validate”, function(frm)
if (biometric_device_ip == device_ip)
msgprint(“Repeated IP”);
validated = false;