amount validation

src/main/resources/static/partials/transaction-list.html

@@ -2,10 +2,11 @@
 	<div>
 		<div><select ng-model='account' ng-change='refreshList()' ng-options="account.name for account in accounts track by account.id"></select></div>
 		<div>
-			<form role="form" ng-submit="postTransaction()">
+			<form name="form" ng-submit="postTransaction()">
 				<div>
-					Betrag: <input ng-model='transaction.amount' type='number' step='0.01' />
+					Betrag: <input name="amount" ng-model='transaction.amount' type='text' required ng-pattern="/^[+-]?(?:\d+(?:[\.,]\d{0,2})?|[\.,]\d{1,2})$/" />
 				</div>
+				<span ng-show="form.amount.$error.pattern"">The value is not a valid value!</span>
 				<div>
 					Kategorie: <select ng-model='transaction.category' size='1'
 						ng-options="category.name for category in categories track by category._links.self.href">
@@ -18,7 +19,7 @@
 					Notiz: <input ng-model='transaction.description' type='text' size='20' />
 				</div>
 				<div>
-					<input type="submit" />
+					<input type="submit" ng-disabled="form.amount.$error.pattern" />
 				</div>
 			</form>