Variable

Hi every one. I am new in this List. My problem is: I determinate the value of a variable in the botton of one page, and I want to use it in the middle of the page, inside a while structure, but I cant´n, inside the while structure I calculate the value of this variable several times until I keep with the value that I want, the last....and I want that in eache of the repetition used the final value of the variable to display a result that I want. If I can´t not explain my self OK, is due to I a few of Inglish...sorry... If any can answer me....please do it.. Best Regard.