Open contacts for a particular account in new page on click on a button and sending email for a selected contact in SFDC

  Visual force code

<apex:page controller="test_Controller" >
<apex:form >
<script language="javascript">
function hello()
{
alert('Hello here ');
}
</script>
<apex:commandButton value="Send Email" action="{!SendEmail}"/>
<apex:pageBlock title="Account Records">
<apex:pageBlockTable value="{!liRecords}" var="li">
<apex:column >
<input type="checkbox" value="{!li.check}" onchecked="{!send}"/>

</apex:column>
<apex:column value="{!li.opr.OpportunityId}" />
<apex:column value="{!li.opr.Role}" />
<apex:column value="{!li.opr.ContactId}" />

</apex:pageBlockTable>

</apex:pageBlock>

</apex:form>

</apex:page>

controllerpublic class test_Controller
{
public String send {

get;
set
{

sendcontacts.add(ApexPages.currentPage().getParameters().get('li.contactid'));
}

}


public List <String> sendcontacts;
public PageReference SendEmail()
{
for(Record r : liRecords)
{
if(r.check==true)
{
Contact c = [Select Id, Name, Email FROM Contact where id=:r.opr.contactId];
if(c!=null)
{
if(c.email!=null)
{
Messaging.reserveSingleEmailCapacity(2);

// Processes and actions involved in the Apex transaction occur next,

// which conclude with sending a single email.


// Now create a new single email message object

// that will send out a single email to the addresses in the To, CC & BCC list.

Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();

// Strings to hold the email addresses to which you are sending the email.

String[] toAddresses = new String[] {c.email};
String[] ccAddresses = new String[] {'smith@gmail.com'};


// Assign the addresses for the To and CC lists to the mail object.

mail.setToAddresses(toAddresses);
mail.setCcAddresses(ccAddresses);

// Specify the address used when the recipients reply to the email.

mail.setReplyTo('support@acme.com');

// Specify the name used as the display name.

mail.setSenderDisplayName('Salesforce Support');

// Specify the subject line for your email address.

mail.setSubject('New Case Created : ' + case.Id);

// Set to True if you want to BCC yourself on the email.

mail.setBccSender(false);

// Optionally append the salesforce.com email signature to the email.

// The email address of the user executing the Apex Code will be used.

mail.setUseSignature(false);

// Specify the text content of the email.

mail.setPlainTextBody('Your Case: ' + case.Id +' has been created');

mail.setHtmlBody('Your case:<b> ' + case.Id +' </b>has been created<p>'+
' View case <a href=https://na1.salesforce.com/'+case.Id+'>click here</a>');

// Send the email you have created.

Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
}
}

}

}


contactid=ApexPages.currentPage().getParameters().get('li.contactid');
contacts=[Select Id, Name, Email FROM Contact where name=:contactid];

return null;
}

public List<OpportunityContactRole> oppList;
public String Oppid {get;set;}
public string contactid;
public List <Contact> contacts;
public List<record> liRecords ;


public List<record> getliRecords()
{
return lirecords;
}

public List<OpportunityContactRole> getoppList()
{
return oppList;
}

public test_Controller()
{
liRecords = new List<record>();
oppList = new list<OpportunityContactRole>();
oppid = ApexPages.currentPage().getParameters().get('id');
System.debug('=======================>>Oppid'+oppid);
oppList = [Select Id, OpportunityId, ContactId, Role FROM OpportunityContactRole where OpportunityId=:oppid];
for(OpportunityContactRole t : opplist)
{
record r = new record();
r.check = false;
r.opr = t;
liRecords.add(r);
}
System.debug('=======================>>Oppid'+oppList );
System.debug('=======================>>Rcords'+lirecords );

}

class record
{
public Boolean check{get;set;}
public OpportunityContactRole opr{get;set;}
}



}