var Weight;                                                                  
var Ht;                                                                  
function Calc(form){                                                                  
var difference;                                                                  
difference = (Weight)  / ((Ht) * (Ht))*10000*4.8;                                                                  
if (difference <15*4.8) {document.all("aa").innerText="您太瘦，应去做个体检，增加营养。";}                                                                  
if (difference >=15*4.8 && difference < 18.5*4.8) {document.all("aa").innerText="您过度苗条，应增加营养和锻炼。";}                                                                  
if (difference >=18.5*4.8 && difference < 22*4.8) {document.all("aa").innerText="恭喜！！您是标准身材,注意保持。";}                                                                  
if (difference >=22*4.8 && difference < 25*4.8) {document.all("aa").innerText="您不苗条了，应该认真看看本站。";}                                                                  
if (difference >=25*4.8 && difference < 30*4.8) {document.all("aa").innerText="您胖了，请看完本站后立即减肥！";}                                                                  
if (difference >=30*4.8 && difference < 40*4.8) {document.all("aa").innerText="您很胖，减肥已是您的头等大事！";}                                                                  
if (difference >=40*4.8 && difference < 900*4.8) {document.all("aa").innerText="您非常胖，您应请医生帮助减肥！";}                                                                  
if (difference >=900*4.8) {document.all("aa").innerText="您不会比青蛙矮,身高单位是(厘米)";} 
document.all("bb").innerText = parseInt(difference);  
}                                                                  
function SetWeight(weight){Weight = weight.value;}                                                                  
function SetHt(ht){Ht = ht.value;}                                                                  
function ClearForm(form){                                                                  
form.Weight.value = "";                                                                  
form.Ht.value = "";                                                                  
form.Fdiff.value = "";                                                                  
form.meaning.value = "";}