hi i am creating "Email" as Custom object. & add to Create a lookup relation for "Email" in contact.Email object have the custom fields of name & email id.if I add one email to the email id equals to contacts then The contact details add to email's releated list.if is not mathes the email id nothing is happen in email - contact related list.If i update that mail id to new one it removes the old contact & update new contact in email related list..I am creating this Trigger but,it show the error in updating time.So How to handle this one for Trigger.new & Trigger.old concept????

trigger trg_Lookup_Contact on Email_Suppression__c (after insert,before update)
{
    for(Email_Suppression__c emailobj : Trigger.New)
    {
        contact[] conobj ;
        if(Trigger.Isupdate)
        {
            conobj = [select name,email,Email_Suppression__c from contact where email =: emailobj.EmailId__c OR email =: Trigger.old.EmailId__c];
        }
        else
        {
            conobj = [select name,email,Email_Suppression__c from contact where email =: emailobj.EmailId__c];
        }
        integer inte = conobj.size();
        for(integer i = 0;i < inte;i++)
        {
            if(emailobj.EmailId__c == conobj[i].email)
            {
                conobj[i].Email_Suppression__c = emailobj.id;
                update conobj[i];
            }
            else
            {
                conobj[i].Email_Suppression__c = null;
                update conobj[i];
            }
        }
    }
}