function display(sID) {

	oObj = document.getElementById(sID);
	if (oObj) {
		oObj.style.display='inline';
	}
}

function hide(sID) {
	oObj = document.getElementById(sID);
	if (oObj) {
		oObj.style.display='none';
	}
}

function gettab_left(id){

if(id==1){
display("box_content1");
document.getElementById("tab1").src		 ='images/tab1.png';
hide("box_content2");
document.getElementById("tab2").src		 ='images/tab2_hide.png';
}else {
display("box_content2");
document.getElementById("tab2").src		 ='images/tab2.png';
hide("box_content1");
document.getElementById("tab1").src		 ='images/tab1_hide.png';
}
}

function gettab_right(id){

if(id==3){
display("box_content3");
document.getElementById("tab3").src		 ='images/tab3.png';
document.getElementById("tab4").src		 ='images/tab4_hide.png';
hide("box_content4");
}else {
display("box_content4");
document.getElementById("tab4").src		 ='images/tab4.png';
document.getElementById("tab3").src		 ='images/tab3_hide.png';
hide("box_content3");
}
}