function trim(s){
	var k, x, z;
	x=s;
	for (k=0; k<s.length; k++){
		if (s.charAt(k)==' ')
		x=s.substring(k+1, s.length);
		else break;
	}
	z=x;
	for (k=(x.length-1); k>0; k--){
		if (x.charAt(k)==' ')
		z=x.substring(0, k);
		else break;
	}
	return z;
}

function isvalidemail(s){
    var k, firstat=false, between=0, count=0, firstdot=false, legalsz="@.";
	s=trim(s);
	if (s.length!=0){
		for (k=0; k<s.length; k++){
			ch=s.charAt(k);
			if (legalsz.indexOf(ch)==0){
			    if (count==0) return false;
			    if (firstat==true) return false;
			    firstat=true;
			}
			else if (legalsz.indexOf(ch)==1){
			    if (count==0) return false;
			    if (firstat){
			        if (between==0) return false;
			        firstdot=true;
			    }
			}
			else{
			    if (firstat) between++;
			    count++;
			}
		}
	}
	return ((firstat && firstdot) ? true : false);
}