<!--
function overwrite(thefield){if (thefield.defaultValue==thefield.value)thefield.value = ""};
function compute(obj) {
with (Math) {
f=(obj.freq.value);
if (!f) return;
f=eval(f);
f2=f*f;
a=148840000*f2*f2;
a/=((f2+424.36)*(f2+148840000)*sqrt(f2+11599.29)*sqrt(f2+544496.41));
a/=0.79434639580229505;
a=20*LOG10E*log(a);
if (round(a)>=0) a=0;
obj.freq.value=round(a);
}	
}
//-->