<apex:column headerValue="Weekdays" headerClass="clsCenter">
                    {!dayslst.Day}----------------------------------------> CAN WE MAKE ANY STYLE OR CSS TO PUT THIS TEXT IN THE MIDDLE OF COLUMn IN PAGEBLOCK TABLE
                </apex:column>
                <apex:column headerValue="Start" headerClass="clsCenter">
                <span style="color:red; font-weight: bold ; vertical-align:Center ; horizontal-align:Center">
                    <apex:outputField value="{!timesheet[dayWithApiname[dayslst.Day]]}">--------------------->>>> CAN WE MAKE ANY STYLE OR CSS TO PUT THIS FIELD IN THE MIDDLE OF COLUMn IN PAGEBLOCK TABLE
                        <apex:inlineEditSupport showOnEdit="saveButton, cancelButton" hideOnEdit="editButton" event="ondblclick" changedStyleClass="myBoldClass" resetFunction="resetInlineEdit"/>
                    </apex:outputField> 
                     </span>
                </apex:column>

public PageReference  Insert_Validation()
{   

    XmlDom dom2 = new XmlDom(FinalObjectXML);
for(xmldom.element e1: dom2.getElementsByTagName('validationRules'))
    {
    MetadataService.MetadataPort service = createService();    
     List<MetadataService.ListMetadataQuery> queries = new List<MetadataService.ListMetadataQuery>(); 
    system.debug('queries'+queries);     
    MetadataService.ListMetadataQuery queryValidationRule = new MetadataService.ListMetadataQuery();
    queryValidationRule.type_x = 'ValidationRule';
    queries.add(queryValidationRule);      
    MetadataService.ListMetadataQuery queryCustomField = new MetadataService.ListMetadataQuery();
    queryCustomField.type_x = 'CustomField';
    queries.add(queryCustomField);     
    MetadataService.FileProperties[] fileProperties = service.listMetadata(queries, 25);
    for(MetadataService.FileProperties fileProperty : fileProperties)

    system.debug('hiiiiii');
    system.debug('e1 value===>'+e1+'====>>>'+e1.getvalue('fullName'));
    MetadataService.ValidationRule ValidationRule1= new MetadataService.ValidationRule();
    ValidationRule1.fullName=e1.getvalue('fullName');


    ValidationRule1.active=Boolean.valueof(e1.getvalue('active'));
    ValidationRule1.errorConditionFormula=customobjectlabel.trim()+'clone__c'+'.checkbox__c=true';//e1.getvalue('errorConditionFormula');
    //ValidationRule.errorDisplayField=e1.getvalue('errorDisplayField');
    ValidationRule1.errorMessage=e1.getvalue('errorMessage');

    system.debug('ValidationRule'+ValidationRule1.fullName+'===>'+ValidationRule1.active+'====>'+ValidationRule1.errorConditionFormula+'=====>'+ValidationRule1.errorMessage);
    MetadataService.AsyncResult[] results12 = service.create(new List<MetadataService.Metadata>{ValidationRule1});   

       system.debug('*****************'+results12);
    }

release date and first version of Metadata API

release date and first version of Metadata API