// ajax

var xmlHttp = GetXmlHttpObject();

function GetXmlHttpObject() {
	
	var objXMLHttp = null;

	if (window.XMLHttpRequest) {
			
		objXMLHttp = new XMLHttpRequest();

	} else if (window.ActiveXObject) {
		
		objXMLHttp = new ActiveXObject("Microsoft.XMLHTTP");
		
	}
	
	return objXMLHttp;

}

function str_replace(search, replace, subject) {
	
	var result = "";
	var oldi = 0;
	
	for (i = subject.indexOf(search); i > -1; i = subject.indexOf(search, i)) {
		result += subject.substring(oldi, i);
		result += replace;
		i += search.length;
		oldi = i;
	}

	return result + subject.substring (oldi, subject.length);

}

function strstr(haystack, needle, bool) {
	
	var pos = 0;
	
	haystack+= '';
    pos = haystack.indexOf(needle);

	if (pos == -1) {

    	return false;
		
	} else {
		
    	if (bool) {
	
	    	return haystack.substr(0, pos);
	
    	} else {
		
			return haystack.slice(pos);
			
		}
	}
}

function switch_display(id) {
			
	var doc_element = document.getElementById(id);
	doc_element.style.display = (doc_element.style.display == 'none') ? '':'none';
			
}

function clearOnInitialFocus(fieldName) {

	var clearedOnce = false;
	
	document.getElementById(fieldName).onfocus = (function() {
		
		if (clearedOnce == false) {
			
			this.value = '';
			this.style.color = '#333333';
			clearedOnce = true;
		
		}
	})
}

function preventDoubleClick(button, send_name) {
	
	if (button.innerHTML != send_name) {

		button.innerHTML = send_name;
		return true;
	
	} else {
	
		return false;
	
	}	
}

function is_numeric(input) {

	return !isNaN(input);
 
}