var txt = new Array();
txt[0]="jpg/top/top_001.jpg";
txt[1]="jpg/top/top_002.jpg";
txt[2]="jpg/top/top_003.jpg";
txt[3]="jpg/top/top_004.jpg";
txt[4]="jpg/top/top_005.jpg";
txt[5]="jpg/top/top_006.jpg";
txt[6]="jpg/top/top_007.jpg";
txt[7]="jpg/top/top_008.jpg";
txt[8]="jpg/top/top_009.jpg";
txt[9]="jpg/top/top_010.jpg";
txt[10]="jpg/top/top_011.jpg";
txt[11]="jpg/top/top_012.jpg";
txt[12]="jpg/top/top_013.jpg";
txt[13]="jpg/top/top_014.jpg";
txt[14]="jpg/top/top_015.jpg";
txt[15]="jpg/top/top_016.jpg";
txt[16]="jpg/top/top_017.jpg";
txt[17]="jpg/top/top_018.jpg";

mmax = 18;
txtno = Math.floor(Math.random() * mmax);
document.write("<img src='"+txt[txtno]+"' alt='' height='300' width='930' />");