Un error en multiplicar datos (VERIFICAR CODIGO PLEASE)

[pepelucho]

<script>
function multiplica(){
if(form.fichero1.value!=''){
valor11=document.form.file1.value*document.form.fi le11.value;
valor1=valor11;
else{valor1=0}
}
if(form.fichero2.value!=''){
valor22=document.form.file2.value*document.form.fi le22.value;
valor2=valor22;
else{valor2=0}
}
if(form.fichero3.value!=''){
valor33=document.form.file3.value*document.form.fi le33.value;
valor3=valor33;
else{valor3=0}
}
if(form.fichero4.value!=''){
valor44=document.form.file4.value*document.form.fi le44.value;
valor4=valor44;
else{valor4=0}
}
if(form.fichero5.value!=''){
valor55=document.form.file5.value*document.form.fi le55.value;
valor5=valor55;
else{valor5=0}
}
if(form.fichero6.value!=''){
valor66=document.form.file6.value*document.form.fi le66.value;
valor6=valor66;
else{valor6=0}
}
total=valor1+valor2+valor3+valor4+valor5+valor6
document.form.total.value=total
}
</script>