function randomimg(){
  var myimages=new Array()
  //specify random images below. You can have as many as you wish
myimages[1]="bannerimages/aquarium.jpg"
myimages[2]="bannerimages/arboretumsummer.jpg"
myimages[3]="bannerimages/bog.jpg"
myimages[4]="bannerimages/botany100garden.jpg"
myimages[5]="bannerimages/botany100woods.jpg"
myimages[6]="bannerimages/botany130lab.jpg"
myimages[7]="bannerimages/botanycampus.jpg"
myimages[8]="bannerimages/botanydesign.jpg"
myimages[9]="bannerimages/botanylab.jpg"
myimages[10]="bannerimages/campusbotanizing.jpg"
myimages[11]="bannerimages/desertgreenhouse.jpg"
myimages[12]="bannerimages/ecologyclass.jpg"
myimages[13]="bannerimages/examiningstains.jpg"
myimages[14]="bannerimages/fieldresearch.jpg"
myimages[15]="bannerimages/fieldtrip.jpg"
myimages[16]="bannerimages/flowersguts.jpg"
myimages[17]="bannerimages/gardenportraits.jpg"
myimages[18]="bannerimages/gardenwinter.jpg"
myimages[19]="bannerimages/greenhouse1.jpg"
myimages[20]="bannerimages/greenhousebotanizing.jpg"
myimages[21]="bannerimages/growthchamber.jpg"
myimages[22]="bannerimages/growthimaging.jpg"
myimages[23]="bannerimages/growthimaging2.jpg"
myimages[24]="bannerimages/labbench.jpg"
myimages[25]="bannerimages/lichens1.jpg"
myimages[26]="bannerimages/lichens2.jpg"
myimages[27]="bannerimages/microscopy.jpg"
myimages[28]="bannerimages/muirwoodspring.jpg"
myimages[29]="bannerimages/muirwoodstrip.jpg"
myimages[30]="bannerimages/pic.jpg"
myimages[31]="bannerimages/pollentubes.jpg"
myimages[32]="bannerimages/prairie.jpg"
myimages[33]="bannerimages/raspberries.jpg"
myimages[34]="bannerimages/roottip.jpg"
myimages[35]="bannerimages/seeding.jpg"
myimages[36]="bannerimages/springblooms.jpg"
myimages[37]="bannerimages/studylichens.jpg"
myimages[38]="bannerimages/teasel.jpg"
myimages[39]="bannerimages/testtubes.jpg"
myimages[40]="bannerimages/tropicalgreenhouse.jpg"
myimages[41]="bannerimages/woodlandfloor.jpg"
//specify corresponding links below
var imagelinks=new Array()
imagelinks[1]=""
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  var ry=Math.floor(Math.random()*myimages.length)
  if (ry==0)
     ry=1
     document.write('<a href="index.htm"><img src="'+myimages[ry]+'" width="850" height="225" border=0 alt="Botany Imagery" usemap="#wiscmap"></a>')
}