             * 2. Section header
             */
             var heightHeader : CGFloat
-            if let height = self.delegate?.colletionView?(self.collectionView!, layout: self, heightForHeaderInSection: section){
+            if let height = self.delegate?.collectionView?(self.collectionView!, layout: self, heightForHeaderInSection: section){
                 heightHeader = height
             }else{
                 heightHeader = self.headerHeight

            let columnIndex  = self.longestColumnIndex()
            top = CGFloat(self.columnHeights.objectAtIndex(columnIndex).floatValue) - minimumInteritemSpacing + sectionInset.bottom
    
            if let height = self.delegate?.colletionView?(self.collectionView!, layout: self, heightForFooterInSection: section){
                footerHeight = height
            }else{
                footerHeight = self.footerHeight

    
    func itemWidthInSectionAtIndex (section : NSInteger) -> CGFloat {
        var insets : UIEdgeInsets
        if let sectionInsets = self.delegate?.collectionView?(self.collectionView!, layout: self, insetForSectionAtIndex: section){
            insets = sectionInsets
        }else{
            insets = self.sectionInset
