I would like to somehow append a string like '@domainname.com' to the end of the username field

Code:
	self.Login = {
		form: '<form method="post" id="login-form" class="login-form">'
			+ '{{#displayUsername}}<label for="username">{{_labelUsername}}</label><input type="text" id="username" name="username"/>{{/displayUsername}}'
			+ '{{#presetJid}}<input type="hidden" id="username" name="username" value="{{presetJid}}"/>{{/presetJid}}'
			+ '{{#displayPassword}}<label for="password">{{_labelPassword}}</label><input type="password" id="password" name="password" />{{/displayPassword}}'
			+ '<input type="submit" class="button" value="{{_loginSubmit}}" /></form>'
	};