javascript 中的变量问题

Question

theFloaters.addItem('followDiv2',6,80,' <img src=images/‘ ＋ aa + ' > <br> <img src=images/close.gif onClick="closeBanner(1);">');

Answer 1

var vgif = images/145x75.gif;
theFloaters.addItem('followDiv2',6,80,' <img src='+vgif+' > <br> <img src=images/close.gif onClick="closeBanner(1);">');

Answer 2

var aa="images/145x75.gif ";
theFloaters.addItem('followDiv2',6,80,' <img src='+aa+' > <br> <img src=images/close.gif onClick="closeBanner(1);">');