function change_subcat(x, formName, domainsSelect, subdomainsSelect){
    var i, j, k, l, opt;
	with(formName){
		l=subdomainsSelect.options.length;
        for (i=0; i<=l-1; i++) {
        	subdomainsSelect.options[l-i]=null;
        }
		for(i=0;i<c2.length;i++){
            if (domainsSelect.value==c2[i].id_c){
				j=0; k=0;
				while (j<c2[i].subc2.length) {
                    opt=new Option(c2[i].subc2[j].subc, c2[i].subc2[j].id_subc);
					subdomainsSelect.options[k+1]=opt;
						if ((c2[i].subc2[j].id_subc==x)){subdomainsSelect.options[k+1].selected=true;}
						k++;
					//}
				j++;
				}
			}
		}
	}
}