function check_text(objlink,maxlimit) {
	if (objlink.value.length > maxlimit){ // if too long...trim it!
		alert("You can not enter here more than " + maxlimit + " symbols!");
		objlink.value = objlink.value.substring(0, maxlimit);
	}
}

function checkFloat(objNumb){
	var Numb = objNumb.value;
	if (Numb.match(/\-?\d*\.?\d+/) != Numb && Numb != "") {
		alert("Number type is invalid!");
		objNumb.value = "";
		objNumb.focus();
	}
}


function checkEmail(objLink){
var Email = objLink.value;
var indexOfAt = Email.indexOf("@");
var indexOfDot = Email.indexOf(".");
if (Email.length != 0){
	if (indexOfAt == -1 || indexOfAt == 0)
		{
			alert("Entered e-mail address seems to be invalid!");
			objLink.value = "";
			objLink.focus();
			return false;
		}
	else if (indexOfDot == -1 || Math.abs(indexOfDot-indexOfAt) == 1 || indexOfDot == Email.length-1)
		{
			alert("Invalid host!");
			objLink.value = "";
			objLink.focus();	
		}
}
}

function isEmpty(objLink){
	var countspace = 0;
	var tmpstr = objLink;
	var objlen = tmpstr.length;
	for (i = 0; i < objlen; i++){
		if (tmpstr.substr(i, 1) == " ") countspace++;
	}
	if (countspace == objlen){
		return true;
	} else {return false;}
}

function checkNumb(objNumb){
var Pattern = "0123456789";
var Numb = objNumb.value;
var Flag = 1;

	if (Numb.length != 0){
	    for (var i=0; i<(Numb.length); i+=1) {
	    	if (Pattern.indexOf(Numb.substring(i,i+1)) == -1) {
		  		Flag = 0;
			}
	    }
		
		if (Flag == 0) {
			alert("Entered value \n["+ Numb +"]\ncontains invalid symbols!");
			objNumb.value = "";
			objNumb.focus();
			return false;
		} else {return true;}

	} else {return true;}
}


	function ErrorMessage(str, obj){
		if(obj) obj.focus();
		alert(str);	
		return false;
	}
	
	function isNotSelected(str, obj, index){
		if(obj.selectedIndex==index){
			ErrorMessage(str, obj);
			return true;
		}
		return false;
	}
  
	function checkFileName(str){
    var result=true;
    var chars=new Array("\\","\/",":","*","?","\"","<",">","|");
    var l=chars.length;
    for(i=0;i<l;i++){
      if(str.indexOf(chars[i])!=-1){
        result = false;
        break;
      }
    }
		return !result;
	}
	
	function checkPassword(obj){
		if( obj ){
			var val=Trim(obj.value);
			var vLen=val.length;
			if(vLen<5 || vLen>8) {
				return ErrorMessage('The password must be at least 5-8 symbols long!', obj);
			}
			else {
			  val = val.replace( /[\~\`\!\@\#\$\%\^\&\*\(\)\_\-\+\=\|\\\}\]\{\[\:\;\"\'\?\.\>\,\<\/\s]/ig , '');
			  if(val.length!=vLen){
			  	return ErrorMessage('The password must contain only alphanumeric characters!', obj);
			  }
			  else {
			  	val = val.replace( /\d/ig , '');
				if( val.length==vLen ){
					return ErrorMessage('The password cannot contain only letters or only digits.', obj);
				}
			  }
			}
		} 
		return true;
	}
	
	function isNotChecked(str, objects){
		var result=true;
		var obj;
		if(objects.length){
			var i
			var l=objects.length;
			obj=objects[0];
			for(i=0;i<l;i++){
				if(objects[i].checked){
					result=false;
					break;
				}
			}
		}
		else{
			obj=objects;
			if(objects.checked) result=false;
		}
		
		if(result) ErrorMessage(str, obj);
		return result;
	}
	
	function isNotChecked2(objects){
		var result=true;
		if(objects.length){
			var i
			var l=objects.length;
			for(i=0;i<l;i++){
				if(objects[i].checked){
					result=false;
					break;
				}
			}
		}
		else{
			if(objects.checked) result=false;
		}

		return result;
	}
	
	function checkLenError(str, obj){
		if(obj) {
			if(Trim(obj.value).length==0){
				ErrorMessage(str, obj);
				return true;
			}
		}
		return false;
	}
	
	function Trim( str ) {
		var strWork;
		strWork = str;
		if( strWork.length != 0 )	{
				while( strWork.length != 0 && strWork.indexOf(" ") == 0)
					strWork = strWork.substring( 1, strWork.length );
					
				while(strWork.length != 0 &&  strWork.lastIndexOf(" ") == strWork.length-1 ) 
					strWork = strWork.substring( 0, strWork.length-1 )
		}
		return strWork;
	}