ExtJS FormPanel.

FormPanel.js

Ext.create('Ext.form.Panel', {
	renderTo: Ext.getBody(),
	url: '/register.aspx',
	method: 'POST',
	items: [
		{
			xtype: 'textfield',
			name: 'username',
			fieldLabel: 'Username'
		}
	],	
	buttons: [
		{
			cls: 'main green',
			text: 'Save',
			disabled: true,
			formBind: true,
			listeners: {
				click: {
					this.up('.form').submit();
				}
			}
		}		
	]
});