VF Page:
<tr class="rowPt10">
                                            <td class="pb18 w20 textRight bold pr10 pl10" valign="top">
                                                <apex:outputText value="Attachments"/>
                                            </td>
                                            
                                            <td class="pb18 greyText">
                                                <apex:inputFile value="{!attachment.body}" fileName="{!attachment.name}" id="file"/>
                                                <apex:commandButton value="Upload" action="{!upload}" />
                                            </td>
                                            
                                        </tr>
          								<tr class="rowPt10">
                                            <td class="pb18 greyText">
                                            <apex:inputTextarea value="{!attachment.Description}"/>
                                            </td>
          										
          								</tr>
                                        <tr class="rowPt10">
                                            
                                            <td colspan="3" class = "leftPadding" >
                                                <apex:dataTable value="{!myList}" var="attachmentRow">
                                                    <apex:column >
                                                            <apex:commandLink action="{!DeleteAttach}" value="X"
                                                                styleClass="btnSave fs8 btnXpadding GreyText left mr10 rc2"
                                                                onclick="if(!confirm('Delete this attachment?')){event.preventDefault(); return false;};">
                                                                <apex:param name="deleteAttachmentId" value="{!attachmentRow.id}" assignTo="{!deleteAttachmentId}" />
                                                            </apex:commandLink>
                                                        </apex:column>
                                                    <apex:column >
                                                            <apex:outputLink value="{!URLFOR($Action.Attachment.Download,attachmentRow.Id)}" target="$_">
                                                                {!attachmentRow.Name}
                                                            </apex:outputLink>
                                                            &nbsp;&nbsp;
                                                            <apex:outputText value="[ By {!attachmentRow.CreatedBy.Name} on {!attachmentRow.CreatedDate}]"/>
                                                    </apex:column>
                                                </apex:dataTable>
                                            </td>
                                        </tr>
                                        
                                    </table>



Controller:


public class SF_AttachmentExecSummaryController {
    public string Pid{get;set;}
    public list<attachment> myList{get; set;}
    Public string deleteAttachmentId{get;set;}
    public SF_AttachmentExecSummaryController(){
        //Pid='a0o17000002AvZvAAK';
    	Pid =ApexPages.currentPage().getParameters().get('Pid');
        system.debug('id:::::'+Pid);
        loadAttachments();
    }
    
    public attachment attachment {
  get {
      if (attachment == null)
        attachment = new Attachment();
      return attachment;
    }
  set;
  }

  public PageReference upload() {

    attachment.OwnerId = UserInfo.getUserId();
    attachment.ParentId = Pid; // the record the file is attached to
    attachment.IsPrivate = true;

    try {
      insert attachment;
    } catch (DMLException e) {
      ApexPages.addMessage(new ApexPages.message(ApexPages.severity.ERROR,'Error uploading attachment'));
      return null;
    } finally {
      attachment = new Attachment(); 
    }
	loadAttachments();
    ApexPages.addMessage(new ApexPages.message(ApexPages.severity.INFO,'Attachment uploaded successfully'));
    return null;
  }
    
    public void loadAttachments(){
        myList = new list<attachment>();//h
        myList = [SELECT CreatedDate,Name,CreatedBy.Name FROM Attachment where parentid =:Pid];//h
    }
    public void DeleteAttach() {
        if (deleteAttachmentId!=null){

             Attachment attachment = [SELECT Id, OwnerId, ParentId from attachment where Id = :deleteAttachmentId];
             //MnPriceApprovalAttachment__c mnPriceApprovalAttachment = [Select Id from MnPriceApprovalAttachment__c where Id=:attachment.ParentId];
             if(userinfo.getUserId()==attachment.OwnerId) {
                try{
                delete attachment ;
                }
                catch (DMLException e) {
                    System.debug('The following exception has occurred: ' + e.getMessage());
                }
            }

             loadAttachments();
        }
    } 
}