代码如下：
<script LANGUAGE="JavaScript"><!-- step = 0; obj = new Image(); function anim(xp,xk,smer) //smer = direction { obj.style.left = x; x += step*smer; if (x>=(xk+xp)/2) { if (smer == 1) step--; else step++; } else { if (smer == 1) step++; else step--; } if (x >= xk) { x = xk; smer = -1; } if (x <= xp) { x = xp; smer = 1; } // if (smer > 2) smer = 3; setTimeout('anim('+xp+','+xk+','+smer+')', 50); } function moveLR(objID,movingarea_width,c) { if (navigator.appName=="Netscape") window_width = window.innerWidth; else window_width = document.body.offsetWidth; obj = document.images[objID]; image_width = obj.width; x1 = obj.style.left; x = Number(x1.substring(0,x1.length-2)); // 30px -> 30 if (c == 0) { if (movingarea_width == 0) { right_margin = window_width - image_width; anim(x,right_margin,1); } else { right_margin = x + movingarea_width - image_width; if (movingarea_width < x + image_width) window.alert("No space for moving!"); else anim(x,right_margin,1); } } else { if (movingarea_width == 0) right_margin = window_width - image_width; else { x = Math.round((window_width-movingarea_width)/2); right_margin = Math.round((window_width+movingarea_width)/2)-image_width; } anim(x,right_margin,1); } } //--></script> <img src="images/4.gif" name="picture" style="position: absolute; top: 70px; left: 30px;" BORDER="0"> <script LANGUAGE="JavaScript"><!-- setTimeout("moveLR('picture',300,1)",10); //--></script> <!--images/4.gif为所左右移动的图片路径-->