apex:message

1<!-- For this example to render properly, you must associate the Visualforce page 
2with a valid account record in the URL. 
3For example, if 001D000000IRt53 is the account ID, the resulting URL should be: 
4https://MyDomain_login_URL/apex/myPage?id=001D000000IRt53
5See the Visualforce Developer's Guide Quick Start Tutorial for more information. -->
6         
7<!-- Page:  -->
8<apex:page controller="MyController" tabStyle="Account">
9    <style>
10    .locationError { color: blue; font-weight: strong;}
11    .employeeError { color: green; font-weight: strong;}
12    </style>
13
14    <apex:form > 
15        <apex:pageBlock title="Hello {!$User.FirstName}!">
16        This is your new page for the {!name} controller. <br/>
17        You are viewing the {!account.name} account.
18
19        <p>Number of Locations: <apex:inputField value="{!account.NumberofLocations__c}" 
20            id="Location_validation"/> 
21        (Enter an alphabetic character here, then click Save to see what happens.) </p>
22           
23        <p>Number of Employees: <apex:inputField value="{!account.NumberOfEmployees}"
24            id="Employee_validation"/> 
25        (Enter an alphabetic character here, then click Save to see what happens.) </p>
26            <p /> 
27        <apex:commandButton action="{!save}" value="Save"/>    
28         <p />
29        <apex:message for="Location_validation" styleClass="locationError" /> <p /> 
30        <apex:message for="Employee_validation" styleClass="employeeError" />   <p />   
31        </apex:pageBlock>  
32    </apex:form>  
33</apex:page>
34
35/*** Controller  ***/
36public class MyController {
37    Account account;
38
39    public PageReference save() {
40    try{
41        update account;
42    }
43    catch(DmlException ex){
44        ApexPages.addMessages(ex);
45    }
46    return null;
47    }
48
49    public String getName() { 
50        return 'MyController';
51    }
52
53    public Account getAccount() {
54        if(account == null)
55        account = [select id, name, numberofemployees, numberoflocations__c from Account
56        where id = :ApexPages.currentPage().getParameters().get('id')];
57        return account;
58    }
59}