//checkval.js
function checkval(v1,v2){
if(!(v1 && v2)){
alert("Error: You must fill all fields: Username and Password to login.\nPlease, make input again...");
return false;}
}
function checkmail(v1){
if(!v1){
alert("Error: You must type your correct email address.\nPlease, make input again...");
return false; } 
if(v1.indexOf('@',1) == -1 || v1.indexOf('.',3)==-1){
alert("Error: You must enter valid email address to send order.\nPlease, make input again...");
return false; } 
}