flying up image, please help!! Options

[xXLoveGoddessXx]

<!-- begin code provided by createblog.com --><br /><!-- begin code provided by createblog.com --><br /><br /><!--Flying Up Ballon Start--><br /><script language="JavaScript1.2"><br />/*<br />Flying Up Ballon *1 picture*<br />Original from http://black.demons.to/<br />fixed to work in XANGA <br />by xanga.com/dorischu<br />*/<br />st=setTimeout;<br />change='';<br />var no = 8; // number of picture appear<br />var speed = 20; // smaller value will move more faster<br />balloon = new Array();<br />balloon[0] = "http://img44.exs.cx/img44/1103/dorischuwingstar4fl.gif";// IMAGE URL<br />balloon[1] = "http://img44.exs.cx/img44/1103/dorischuwingstar4fl.gif";<br />balloon[2] = "http://img44.exs.cx/img44/1103/dorischuwingstar4fl.gif";<br />var maxballoon = 2;   <br />var ns4up = (document.layers) ? 1 : 0;   <br />var ie4up = (document.all) ? 1 : 0;<br />var dx, xp, yp;     <br />var am, stx, sty;   <br />var i, doc_width = 500, doc_height = 600;<br />if (ns4up) {<br />doc_width = self.innerWidth;<br />doc_height = self.innerHeight - 50;<br />} else if (ie4up) {<br />doc_width = document.body.clientWidth;<br />doc_height = document.body.clientHeight -50;<br />}<br />dx = new Array();<br />xp = new Array();<br />yp = new Array();<br />am = new Array();<br />stx = new Array();<br />sty = new Array();<br />j = maxballoon;<br />for (i = 0; i < no; ++ i) {<br />dx[i] = 0;                         <br />xp[i] = Math.random()*(doc_width-50);   <br />yp[i] = Math.random()*doc_height;<br />am[i] = Math.random()*20;          <br />stx[i] = 0.02 + Math.random()/10;  <br />sty[i] = 0.7 + Math.random();      <br />if (ns4up) {                      <br /> if (i == 0) {<br />  document.write("<layer name=\"dot"+ i +"\" left=\"15\" top=\"500\" visibility=\"show\"><img src=\"" + balloon[j] + "\" border=\"0\"></layer>");<br /> } else {<br />  document.write("<layer name=\"dot"+ i +"\" left=\"15\" top=\"500\" visibility=\"show\"><img src=\"" + balloon[j] + "\" border=\"0\"></layer>");<br />   }<br />} else if (ie4up) {<br /> if (i == 0) {<br />  document.write("<div id=\"dot"+ i +"\" style=\"POSITION: abso"+change+"lute; Z-INDEX: "+ i +"; VISIBILITY: visible; TOP: 500px; LEFT: 15px;\"><img src=\"" + balloon[j] + "\" border=\"0\"></div>");<br /> } else {<br />  document.write("<div id=\"dot"+ i +"\" style=\"POSITION: abso"+change+"lute; Z-INDEX: "+ i +"; VISIBILITY: visible; TOP: 500px; LEFT: 15px;\"><img src=\"" + balloon[j] + "\" border=\"0\"></div>");<br />    }<br />}<br />if (j == 0) { j = maxballoon; } else { j -= 1; }<br />}<br />function snowNS() {   <br />for (i = 0; i < no; ++ i) {   <br /> yp[i] -= sty[i];<br /> if (yp[i] < 0) {<br />  xp[i] = Math.random()*(doc_width-am[i]-30);<br />  yp[i] = doc_height;<br />  stx[i] = 0.02 + Math.random()/10;<br />  sty[i] = 0.7 + Math.random();<br />  doc_width = self.innerWidth;<br />  doc_height = -1550;<br /> }<br /> dx[i] += stx[i];<br /> document.layers["dot"+i].top = yp[i];<br /> document.layers["dot"+i].left = xp[i] + am[i]*Math.sin(dx[i]);<br />}<br />st("snowNS()", speed);<br />}<br />function snowIE() {   <br />for (i = 0; i < no; ++ i) {   <br /> yp[i] -= sty[i];<br /> if (yp[i] < 0) {<br />  xp[i] = Math.random()*(doc_width-am[i]-30);<br />  yp[i] = doc_height;<br />  stx[i] = 0.02 + Math.random()/10;<br />  sty[i] = 0.7 + Math.random();<br />  doc_width = document.body.clientWidth;<br />  doc_height = document.body.clientHeight -50;<br /> }<br />dx[i] += stx[i];<br />document.all["dot"+i].style.pixelTop = yp[i];<br />document.all["dot"+i].style.pixelLeft = xp[i] + am[i]*Math.sin(dx[i]);<br />}<br />st("snowIE()", speed);<br />}<br />if (ns4up) {<br />snowNS();<br />} else if (ie4up) {<br />snowIE();<br />}<br />// End --><br /></script><br /><!-- end code provided by createblog.com --><br /><!-- end code provided by createblog.com -->

that's the code for flying up image, but the problem is that the image doesn't start all the way from the bottom, instead, it starts from the middle....does anyone know how to make the image start from the bottom of the page?....any help will be appreciated