贷款计算器

阿门 不知道计算公式...         我直接ctrl+c了

<SCRIPT language=JavaScript>
<!--
function processForm(form)
{
var score=0,temp=0,temp1=0,rate=0,i=0,temp2=0,temp3=0;
rate = form.c3.value / 100 ;
score = form.c1.value * rate ;
temp2 = 1 + rate ;
temp3 = temp2;
for(i=1;i<form.c2.value;i++)
{
   temp2 = temp2 * temp3 ;
}
temp1 = temp2 - 1 ;
score = score * temp2 / temp1;
form.result.value = score;
}
//-->
</SCRIPT>
<SCRIPT language=JavaScript>
function runjs1(obj){dj1=parseFloat(obj.dj1.value)
chsh1=parseInt(obj.chsh1.value)/10
nsh1=parseInt(obj.nsh1.value)
qsh=12*nsh1
{if(nsh1<6)lx=parseFloat(0.0477)
if(nsh1>=6)lx=parseFloat(0.0504)}
ylx=lx/12
mj1=parseFloat(obj.mj1.value)
fkz1=dj1*mj1
dkz1=fkz1*chsh1
yj1=(ylx/(1-(1/(Math.pow(1+ylx,qsh)))))*dkz1
hkz1=yj1*qsh
obj.dkz1.value=Math.round(dkz1*100,5)/100
obj.shf1.value=Math.round((fkz1-dkz1)*100,5)/100
obj.yj1.value=Math.round(yj1*100,5)/100
obj.fkz1.value=Math.round(fkz1*100,5)/100
obj.lxfd1.value=Math.round((hkz1-dkz1)*100,5)/100
obj.hkz1.value=Math.round(hkz1*100,5)/100 }
</SCRIPT>

<table width="260" border="0" cellspacing="0" cellpadding="0">
          <tr>
            <td >
              <table width="80%" border="0" cellspacing="1" cellpadding="5" align="center">
                <form action="" method=post name=formt>
                  <tr >
                    <td width="52%" height="110" align="left" class="font"> 单价：
                      <input maxlength=6 name=dj1 size=10>
                      元/㎡<br>
                      面积：
                      <input maxlength=7 name=mj1 size=10>
                      ㎡<br>
                      按揭成数：
                      <select name=chsh1 size=1 style="FONT-SIZE: 12px">
                        <option selected value=8>8成</option>
                        <option value=7>7成</option>
                        <option value=6>6成</option>
                        <option value=5>5成</option>
                        <option value=4>4成</option>
                        <option value=3>3成</option>
                        <option value=2>2成</option>
                      </select>
                      <br>
                      按揭年数：
                      <select name=nsh1 size=1 style="FONT-SIZE: 12px">
                        <option value=2>2年(24期)</option>
                        <option value=3>3年(36期)</option>
                        <option value=4>4年(48期)</option>
                        <option value=5>5年(60期)</option>
                        <option value=6>6年(72期)</option>
                        <option value=7>7年(84期)</option>
                        <option value=8>8年(96期)</option>
                        <option value=9>9年(108期)</option>
                        <option value=10>10年(120期)</option>
                        <option selected value=15>15年(180期)</option>
                        <option value=20>20年(240期)</option>
                        <option value=25>25年(300期)</option>
                        <option value=30>30年(360期)</option>
                      </select>
                    </td>
                  
                  </tr>
              
              
              
              
                  <tr bgcolor="#FFFFFF">
                    <td width="52%" height="36" align="left">
                      <input name=math1 onClick=runjs1(this.form) type=button value=开始计算>
                      <input name=Submit21 type=reset value=重新计算>
                    </td>
                  </tr>
              
                  <tr bgcolor="#FFFFFF">
                    <td width="52%" height="36" align="left">
                      房款总额：
                      <input name=fkz1 size=10>
                      元<br>
                      贷款总额：
                      <input name=dkz1
            size=10>
                      元<br>
                      首期付款：
                      <input name=shf1 size=10>
                      元<br>
                      月均还款：
                      <input name=yj1 size=10>
                      元<br>
                      还款总额：
                      <input name=hkz1 size=10>
                      元<br>
                      支付息款：
                      <input name=lxfd1 size=10>
                      元
                    </td>
                  </tr>
                </form>
              </table>
            </td>
          </tr>
        </table>