如何使用php在一个Excel中自定义两张Excel的Excel数据？

I am using codeigniter framework, in this I am creating excel file with MySQL data's. I need to create header table (ie, first loop) data's into first sheet, detail table (ie, second loop) data's into second sheet. Below I have given my code, this generating in same sheet with next next data's. Can any one give some ideas to solve this.I am using codeigniter framework, in this I am