function trim(s) 
{ 
    var l=0; var r=s.length -1; 
    while(l < s.length && s[l] == ' ') 
    {     l++; } 
    while(r > l && s[r] == ' ') 
    {     r-=1;     } 
    return s.substring(l, r+1); 
} 

function validate_required(field,alerttxt)
{
with (field)
{
  if (value==null||trim(value)=="")
  {
  alert(alerttxt);return false;
  }
  else
  {
  return true;
  }
}
}

function validate_email(field,alerttxt)
{
with (field)
  {
  apos=value.indexOf("@");
  dotpos=value.lastIndexOf(".");
  if (apos<1||dotpos-apos<2)
    {alert(alerttxt);return false;}
  else {return true;}
  }
}