// Check e-mail for necessary symbol, if found -then return true        
function CheckEmail_quest(cStringOriginal, oForm, lang)
{ 
 var FirstPositNotBlank;
 var LastPositNotBlank;
 var positUho;
 var positLastPoint;
 var ValidSymbols = "qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM1234567890-._";
 var ValidSymbolsAfterUhoBeforeLastPoint = "qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM1234567890-.";
 var ValidSymbolsAfterLastPoint = "qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM ";
 var cSymbol;
 var cString;
 var serrcheckemail;
// if (isEmpty(lang))
// {
// 	lang="RU";
// }

 if (lang=="RU")
 { serrcheckemail="Ошибка в е-mail!";}
 if (lang=="UA")
 { serrcheckemail="Помилка в е-mail!";}
 if (lang=="EN")
 { serrcheckemail="e-mail: invalid value!";}

	for (var i = 0; i < cStringOriginal.length; i++)
    {
       if ((cStringOriginal.substring (i,i+1) !=" ") && (cStringOriginal.substring (i,i+1) !="<"))
       {
        FirstPositNotBlank = i;
        break;
       }
    }
 
 
        for (var i = cStringOriginal.length; i >= 0; i--)
    {
                if ((cStringOriginal.substring (i-1,i) !=" ") && (cStringOriginal.substring (i-1,i) !=">"))
             {
                                LastPositNotBlank = (i-1);
                                break;
                         }      
        }         
        cString = cStringOriginal.substring(FirstPositNotBlank, LastPositNotBlank+1);     
        positUho = cString.indexOf("@",0); //position of @

        if (!(positUho <= 0 ))
        {
        //check symbols before @
                for (var i = 0; i < positUho; i++)
        {
                cSymbol = cString.substring(i,i+1);
                if (ValidSymbols.indexOf(cSymbol,0) == -1)
                    {

                   //              window.alert(serrcheckemail);
                  //               oForm.e_mail.focus();
                 return serrcheckemail;
                        }
        }
         }
        else 
        {
              //  window.alert(serrcheckemail);
       //        oForm.e_mail.focus();
        return serrcheckemail;
        }
 
 //check symbols after @ and before last point
        positLastPoint= cString.lastIndexOf(".");

        if ((positLastPoint > 0) && (positLastPoint > positUho+1))
        {
                for (var i = positUho+1; i < positLastPoint; i++)
        {
            cSymbol = cString.substring(i,i+1);
                        if (ValidSymbolsAfterUhoBeforeLastPoint.indexOf(cSymbol,0) == -1)
                    {

                     //            window.alert(serrcheckemail);
                    //             oForm.e_mail.focus();
                 return serrcheckemail;
                        }    
                }       
        }
        else
        {
               // window.alert(serrcheckemail);
               // oForm.e_mail.focus();
        return serrcheckemail;
        }
 //check length and validate symbols after last point
        if ((((cString.length - 1) - positLastPoint) >= 2) &&  (((cString.length - 1) - positLastPoint) <=4 ))
        {
                for (var i = positLastPoint+1 ; i < cString.length; i++)
        {
                cSymbol = cString.substring(i,i+1);
                        if (ValidSymbolsAfterLastPoint.indexOf(cSymbol ,0) == -1)
                    {
                      //           window.alert(serrcheckemail);
                     //            oForm.e_mail.focus();
                 return serrcheckemail;
                        };    
                }       
        }
        else
        {

                window.alert(serrcheckemail);
 //               oForm.e_mail.focus();
        return serrcheckemail;
        }
 return "";
}