i want to create this type of grid field can any one guide me?

import net.rim.device.api.ui.Field; import net.rim.device.api.ui.Manager;

public class GridFieldManager extends Manager { private int[] columnWidths; private int columns; private int allRowHeight = -1;

public GridFieldManager(int columns, long style) {
    super(style);
    this.columns = columns;
}


public GridFieldManager(int[] columnWidths, long style) {
    super(style);
    this.columnWidths = columnWidths;
    this.columns = columnWidths.length;
}

public GridFieldManager(int[] columnWidths, int rowHeight, long style) {
    this(columnWidths, style);
    this.allRowHeight  = rowHeight;
}

protected boolean navigationMovement(int dx, int dy, int status, int time) {

    int focusIndex = getFieldWithFocusIndex();
    while(dy > 0) {
        focusIndex += columns;
        if (focusIndex >= getFieldCount()) {
            return false; // Focus moves out of this manager
        }
        else {
            Field f = getField(focusIndex);
            if (f.isFocusable()) { // Only move the focus onto focusable fields
                f.setFocus();
                dy--;
            }
        }
    }
    while(dy < 0) {
        focusIndex -= columns;
        if (focusIndex < 0) {
            return false;
        }
        else {
            Field f = getField(focusIndex);
            if (f.isFocusable()) {
                f.setFocus();
                dy++;
            }
        }
    }

    while(dx > 0) {
        focusIndex ++;
        if (focusIndex >= getFieldCount()) {
            return false;
        }
        else {
            Field f = getField(focusIndex);
            if (f.isFocusable()) {
                f.setFocus();
                dx--;
            }
        }
    }
    while(dx < 0) {
        focusIndex --;
        if (focusIndex < 0) {
            return false;
        }
        else {
            Field f = getField(focusIndex);
            if (f.isFocusable()) {
                f.setFocus();
                dx++;
            }
        }
    }
    return true;
}


protected void sublayout(int width, int height) {
    int y = 0;
    if (columnWidths == null) {
        columnWidths = new int[columns];
        for(int i = 0; i < columns; i++) {
            columnWidths[i] = width/columns;
        }
    }
    Field[] fields = new Field[columnWidths.length];
    int currentColumn = 0;
    int rowHeight = 0;
    for(int i = 0; i < getFieldCount(); i++) {
        fields[currentColumn] = getField(i);
        layoutChild(fields[currentColumn], columnWidths[currentColumn], height-y);
        if (fields[currentColumn].getHeight() > rowHeight) {
            rowHeight = fields[currentColumn].getHeight();
        }
        currentColumn++;
        if (currentColumn == columnWidths.length || i == getFieldCount()-1) {
            int x = 0;
            if (this.allRowHeight >= 0) {
                rowHeight = this.allRowHeight;
            }
            for(int c = 0; c < currentColumn; c++) {
                long fieldStyle = fields[c].getStyle();
                int fieldXOffset = 0;
                long fieldHalign = fieldStyle & Field.FIELD_HALIGN_MASK;
                if (fieldHalign == Field.FIELD_RIGHT) {
                    fieldXOffset = columnWidths[c] - fields[c].getWidth();
                }
                else if (fieldHalign == Field.FIELD_HCENTER) {
                    fieldXOffset = (columnWidths[c]-fields[c].getWidth())/2;
                }

                int fieldYOffset = 0;
                long fieldValign = fieldStyle & Field.FIELD_VALIGN_MASK;
                if (fieldValign == Field.FIELD_BOTTOM) {
                    fieldYOffset = rowHeight - fields[c].getHeight();
                }
                else if (fieldValign == Field.FIELD_VCENTER) {
                    fieldYOffset = (rowHeight-fields[c].getHeight())/2;
                }

                setPositionChild(fields[c], x+fieldXOffset, y + fieldYOffset);
                x += columnWidths[c];
            }
            currentColumn = 0;
            y += rowHeight;
        }
        if (y >= height) {
            break;
        }
    }
    int totalWidth = 0;
    for(int i = 0; i < columnWidths.length; i++) {
        totalWidth += columnWidths[i];
    }
    setExtent(totalWidth, Math.min(y, height));
}

}