function check_form(){
                    if (document.getElementById('form_lca_input').npa.value.length<3){
                        alert("Please input 3-character area code.");
                        document.getElementById('form_lca_input').npa.focus();
                        return false;
                    }
                    if (document.getElementById('form_lca_input').nxx.value.length<3){
                        alert("Please input 3-character prefix.");
                        document.getElementById('form_lca_input').nxx.focus();
                        return false;
                    }
                    var found = false;
                    for (var ii = 0; ii < v_npa.length; ii++){
                            if (v_npa[ii] == document.getElementById('form_lca_input').npa.value){
                                document.getElementById('form_lca_input').provider.value = v_provider[ii];
                                document.getElementById('form_lca_input').state.value = v_state[ii];
                                found = true;
                                break;
                            }
                    }
                    if (!found){
                        alert("\nThe area code you input is not valid.\nPlease input 3-character area code.\n");
                        document.getElementById('form_lca_input').npa.focus();
                        return false;
                    }

                    var list = document.getElementById('form_lca_input').showarea.value;
                    if (list.length == 0) return true;
                    var tmp = "";
                    var ff = false;
                    for (var jj = 0; jj < list.length; jj++){
                        if (list.charAt(jj) == ' ' && tmp !=""){
                            ff = false;
                            for (var kk = 0; kk < v_npa.length; kk++){
                                if (v_npa[kk] == tmp){
                                    ff = true;
                                    break;
                                 }
                             }
                           if (!ff){
                                alert("\nThe show area code you input is not valid.\nPlease re-input.\n");
                                document.getElementById('form_lca_input').showarea.focus();
                                return false;
                           }
                           tmp = "";
                        }else{
                            tmp += list.charAt(jj);
                        }
                    }

                    if (tmp != ""){
                        ff = false;
                        for (var kk = 0; kk < v_npa.length; kk++){
                            if (v_npa[kk] == tmp){
                                ff = true;
                                 break;
                            }
                         }
                        if (!ff){
                            alert("\nThe show area code you input is not valid.\nPlease re-input.\n");
                            form_lca_input.showarea.focus();
                            return false;
                        }
                     }
                     return true;
}

function KeyPressed(){
	if(event.keyCode==13) event.returnValue = true; else if (event.keyCode != 32 && (event.keyCode < 48 || event.keyCode > 57)) event.returnValue = false;
}