在aspx页面中使用c＃代码块 - 在块之间使用变量

I have an aspx page with some c# code blocks in it and I am trying to use a variable from the first block in the second block. I've tried lots of different things to make the variable public and available but haven't managed it. Can someone point out/give me a clue as to where I am going wrong please?I have an aspx page with some c# code blocks in