代码如下： <!--脚本说明：把如下代码加入<body>区域中:--> <script LANGUAGE="JAVASCRIPT"> <!-- hide this script tag's contents from old browsers function ClearForm(form){ form.weight.value = ""; form.height.value = ""; form.bmi.value = ""; form.my_comment.value = ""; } function bmi(weight, height) { bmindx=weight/eval(height*height); return bmindx; } function checkform(form) { if (form.weight.value==null||form.weight.value.length==0 || form.height.value==null||form.height.value.length==0){ alert("\nPlease complete the form first"); return false; } else if (parseFloat(form.height.value) <= 0|| parseFloat(form.height.value) >=500|| parseFloat(form.weight.value) <= 0|| parseFloat(form.weight.value) >=500){ alert("\nReally know what you're doing? \nPlease enter values again. \nWeight in kilos and \nheight in cm"); ClearForm(form); return false; } return true; } function computeform(form) { if (checkform(form)) { yourbmi=Math.round(bmi(form.weight.value, form.height.value/100)); form.bmi.value=yourbmi; if (yourbmi >30) { form.my_comment.value="不要在闹了!!!"; } else if (yourbmi >28 && yourbmi <=30) { form.my_comment.value="您是猪吗?"; } else if (yourbmi >23 && yourbmi <=28) { form.my_comment.value="两头猪也没有你重吧?"; } else if (yourbmi >21 && yourbmi <=23) { form.my_comment.value="您现在是偏胖,应该注意饮食!"; } else if (yourbmi >=19 && yourbmi <=21) { form.my_comment.value="哇!!!您太苗条了! 是标准身材"; } else if (yourbmi >=18 && yourbmi <19) { form.my_comment.value="您是不是营养不良?????"; } else if (yourbmi >=17 && yourbmi <18) { form.my_comment.value="这个不是骨头吗????"; } else if (yourbmi <17) { form.my_comment.value="按照生物学来说这种生物是不能生存的"; } } return; } // -- done hiding from old browsers --> </script> <form NAME="BMI" method="POST"> <table border="1"> <tr> <td><font color="red"><div align="center"><center><p>体重</font> (kg)</td> <td align="center"><font color="red"><div align="center"><center><p>身高</font>(cm)</td> <td align="center"><font color="blue"><div align="center"><center><p>健康值</font></td> <td align="center"><font color="blue"><div align="center"><center><p>电脑对您的评价</font></td> </tr> <tr align="center"> <td><input TYPE="TEXT" NAME="weight" SIZE="6" onFocus="this.form.weight.value=''"></td> <td><input TYPE="TEXT" NAME="height" SIZE="6" onFocus="this.form.height.value=''"></td> <td><input TYPE="TEXT" NAME="bmi" SIZE="5"></td> <td><input TYPE="TEXT" NAME="my_comment" size="40"></td> </tr> </table> <div align="center"><center><p><input TYPE="button" VALUE="确定" onClick="computeform(this.form)"> <input TYPE="reset" VALUE="取消" onClick="ClearForm(this.form)"> </p> </center></div> </form>
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