Alternativa uso eval() javascript en html

// Recuperación del date en el window Parent
argumentos=location.search.split('&');
if (argumentos<3) {
alert("faltan argumentos en la URL...");
return false;
}
//var str = location.search.substring(1, location.search.length);
// alert('mnth1='+mnth1);
numDays = numDaysIn(mnth1,year);
eval(
"window.opener.document.forms[0]." + argumentos[0].substring(1,argumentos[0].length)).length = numDays;
for (i=27;i<numDays;i++) {
eval("window.opener.document.forms[0]." + argumentos[0].substring(1,argumentos[0].length)).options.text = i+1;
}
eval("window.opener.document.forms[0]." + argumentos[1].substring(0,argumentos[1].length)).selectedIndex = mnth1;
eval(
"window.opener.document.forms[0]." + argumentos[2].substring(0,argumentos[2].length)).selectedIndex = year-min_year;
eval(
"window.opener.document.forms[0]." + argumentos[0].substring(1,argumentos[0].length)).selectedIndex = sstr-1;