document.getElementById使用变量返回null以将Id传递给函数onclick

I have two searches of a JSON file producing results on two separate parts of the page in two separate divs. The results are produced by for loops, and many hidden divs are created in each of the two results divs, which are displayed by onclick. The id's in div #1 are as "a"+i, where i is the for loop counter. Div #2 is similar with the hidden id's being "aa"+i. Must not have duplicate ID's. The document.getElementById in the function unhyde() is null, if I pass the hidden div's id to display it as thus:I have two searches of a JSON file producing re