function changevalue(formfield, fieldvalue, activity) {
    if (activity == 'add') {
        if (formfield.value == fieldvalue) {
            formfield.value = '';
        }
    }
    else {
        if (formfield.value == '') {
            formfield.value = fieldvalue;
        }
    }
}


function echeck(str) {

	var at="@"
	var dot="."
	var lat=str.indexOf(at)
	var lstr=str.length
	var ldot=str.indexOf(dot)
	if (str.indexOf(at)==-1){
	   return false
	}

	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
	   return false
	}

	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
	    return false
	}

	 if (str.indexOf(at,(lat+1))!=-1){
	    return false
	 }

	 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
	    return false
	 }

	 if (str.indexOf(dot,(lat+2))==-1){
	    return false
	 }
	
	 if (str.indexOf(" ")!=-1){
	    return false
	 }

		 return true					
}

function trim(str, chars) {
	return ltrim(rtrim(str, chars), chars);
}
 
function ltrim(str, chars) {
	chars = chars || "\\s";
	return str.replace(new RegExp("^[" + chars + "]+", "g"), "");
}
 
function rtrim(str, chars) {
	chars = chars || "\\s";
	return str.replace(new RegExp("[" + chars + "]+$", "g"), "");
}


		function show_highlight_over(thumb_no){
			var highlight_thumb = document.getElementById("highlight_thumb"+thumb_no);
			var newImage = "url(images/highlight_thumb"+thumb_no+"_ovr.png)";
        	highlight_thumb.style.backgroundImage = newImage;

			
		}
		function show_highlight_reset(){
			var highlight_thumb = "";
			var count = 1;
			var newImage = "";
			
			for(count = 1; count <= 4; count++){
			
				highlight_thumb = document.getElementById("highlight_thumb"+count);		
				newImage = "url(images/highlight_thumb"+count+".png)";
	        	highlight_thumb.style.backgroundImage = newImage;	
			
			}
			
		}
		
		
		
				function validate_frmAskNow(){
					
					var obj = document.getElementById("frmAskNow");
					
					ajaxFunction_call_Func("includes/ajax_validate.php?text_code="+obj.code.value, "POST", "div_result", execute_form_frmAskNow, "checking verify code ... ");
					
				}
				
				function execute_form_frmAskNow(){
					
					var obj = document.getElementById("frmAskNow");
					
					var error_name = document.getElementById("frmAskNow.error_name");
					var error_email_address = document.getElementById("frmAskNow.error_email_address");
					var error_phone = document.getElementById("frmAskNow.error_phone");
					var error_comment = document.getElementById("frmAskNow.error_comment");
					var valid_code = document.getElementById("valid_code");
					
					var pass = true;
					
					
					error_name.innerHTML = " <br />";
					error_email_address.innerHTML = " <br />";
					error_phone.innerHTML = " <br />";
					error_comment.innerHTML = " <br />";
					
					if(obj.name.value == "Name" || trim(obj.name.value) == ""){
						error_name.innerHTML = "Please add name";
						pass = false;
					}
					if(obj.email_address.value == "Email Address" || trim(obj.email_address.value) == ""){
						error_email_address.innerHTML = "Please add email address";
						pass = false;
					}
					else{
						if(echeck(obj.email_address.value) == false){
							error_email_address.innerHTML = "Please add a valid email address";
							pass = false;
						}
					}
					if(obj.phone.value == "Phone Number" || trim(obj.phone.value) == ""){
						error_phone.innerHTML = "Please add phone<br />";
						pass = false;
					}
					if(obj.comment.value == "Comments/Questions" || trim(obj.comment.value) == ""){
						error_comment.innerHTML = "Please add comment<br />";
						pass = false;
					}
					
					if(valid_code.value == "false"){
						pass = false;								
					}
					
					if(pass == true){
						obj.submit();
					}
					
				}