JavaScript Base instance: How to calculate 24 points (2)

function test (EXPN,A,B,C,D,M1,M2,M3)
{
var exp;
VAR ret;
Exp = genexpress (EXPN,A,B,C,D,M1,M2,M3);//Generate a calculation expression
Eval ("ret =" +exp);
if (Ret-24 < 0.1 && ret-24 >= 0)
{
Exp = Exp.replace (";", "");
Exp = ReplaceAll (exp, "*", "X");
Exp = ReplaceAll (exp, "/", "a");
var have = false;
for (var i=0; i<counter; i++)
{
if (exp = = Answer[i])
{
have = true;
Break
}
}
if (!have)
{
Answer[counter] = exp;
counter++;
Log ("<font color=red><b>" +counter+ ":" +exp+ "</b></font>");
}

}
}

function ReplaceAll (Streng, Soeg, Erstat)
{
var st = Streng;
if (soeg.length = 0)
Return St;
var idx = st.indexof (SOEG);
while (idx >= 0)
{
st = st.substring (0,IDX) + Erstat + st.substr (idx+soeg.length);
IDX = St.indexof (SOEG);
}
Return St;
}

var n = new Array ();//four digits

Receives the number of four input boxes, invokes the main program
function Funcount ()
{
N[0] = Document.forms[0].fa.value;
n = document.forms[0].fb.value;
n = document.forms[0].fc.value;