function contact_us_send()
{
  
  error_msg = '';
  
  if($('contact_us_name').value.length == 0) error_msg += '* Name  required \n';
  if($('contact_us_email').value.length == 0) error_msg += '* Email  required \n';
  
  if($('contact_us_email').value.length>0) if(!email_validation($('contact_us_email').value)) error_msg += '* Invalid Email Address\n';
  
  if($('contact_us_subject').value.length == 0) error_msg += '* Subject  required \n';
  if($('contact_us_message').value.length == 0) error_msg += '* Message  required \n';
  
  if(error_msg.length==0)
  {
    name = $('contact_us_name').value;
    email = $('contact_us_email').value;
    subject = $('contact_us_subject').value;
    message = $('contact_us_message').value;
    
    message = str_ireplace("\n","|",message);
    message = str_ireplace("\r","|",message);
    message = str_ireplace("\n\r","|",message);
    message = str_ireplace("\r\n","|",message);
        
    //alert(message);
    
    Modalbox.show('c.php?is_sent=1&name='+name+'&email='+email+'&subject='+subject+'&message='+message, {title: 'Contact Us', width: 500});
  }
  else
  {
    alert(error_msg);
  }

}

function email_validation(email) {
   var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;   
   if(reg.test(email) == false) {      
      return false;
   }
   
   return true;
}

// {{{ str_ireplace
function str_ireplace ( search, replace, subject ) {
    // Case-insensitive version of str_replace().
    // 
    // +    discuss at: http://kevin.vanzonneveld.net/techblog/article/javascript_equivalent_for_phps_str_ireplace/
    // +       version: 810.621
    // +   original by: Martijn Wieringa
    // +      input by: penutbutterjelly
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +    tweaked by: Jack
    // +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   bugfixed by: Onno Marsman
    // *     example 1: str_ireplace('l', 'l', 'HeLLo');
    // *     returns 1: 'Hello'

    var i, k = '';
    var searchl = 0;

    search += '';
    searchl = search.length;
    if (!(replace instanceof Array)) {
        replace = new Array(replace);
        if (search instanceof Array) {
            // If search is an array and replace is a string,
            // then this replacement string is used for every value of search
            while (searchl > replace.length) {
                replace[replace.length] = replace[0];
            }
        }
    }

    if (!(search instanceof Array)) {
        search = new Array(search);
    }
    while (search.length>replace.length) {
        // If replace has fewer values than search,
        // then an empty string is used for the rest of replacement values
        replace[replace.length] = '';
    }

    if (subject instanceof Array) {
        // If subject is an array, then the search and replace is performed
        // with every entry of subject , and the return value is an array as well.
        for (k in subject) {
            subject[k] = str_ireplace(search, replace, subject[k]);
        }
        return subject;
    }

    searchl = search.length;
    for (i = 0; i < searchl; i++) {
        reg = new RegExp(search[i], 'gi');
        subject = subject.replace(reg, replace[i]);
    }

    return subject;
}// }}}