var clickmessage="Copyright TMC Measuring Instruments Pvt. Ltd." 

function disableclick(e) { 
if (document.all) { 
if (event.button==2||event.button==3) { 
if (event.srcElement.tagName=="IMG"){ 
alert(clickmessage); 
return false; 
} 
} 
} 
else if (document.layers) { 
if (e.which == 3) { 
alert(clickmessage); 
return false; 
} 
} 
else if (document.getElementById){ 
if (e.which==3&&e.target.tagName=="IMG"){ 
alert(clickmessage) 
return false 
} 
} 
} 

function associateimages(){ 
for(i=0;i<document.images.length;i++) 
document.images[i].onmousedown=disableclick; 
} 

if (document.all||document.getElementById) 
document.onmousedown=disableclick 
else if (document.layers) 
associateimages()