// JavaScript Document

function validate(formobj)
{
	if(emptyField(formobj.file1))	
	{
	alert("Please select a Picture File ");
	formobj.file1.focus();
	return(false);
	}
	
	var filenmchk = chkExtension(document.frmshop.file1)
	if(!filenmchk)
	{
		return false;
	}
	return true;
}



function chkExtension(txtfield)
{
	var filename,filenamelen
	var fileext,fileextlen
	var allowedtypes = [".jpg",".JPG",".jpeg",".JPEG",".gif",".GIF"]
	var dotpos
	filename = txtfield.value
	filenamelen = filename.length
	dotpos = filename.lastIndexOf(".")
	fileextlen = (filenamelen - dotpos - 1)
	
	if (fileextlen >= 3 && fileextlen <= 4) //this allows files with a min of 3 and max of 4 chars in their extension
	{
	fileext = filename.substring(dotpos,filenamelen)
	//alert (fileext)
		for(var ctr=0;ctr<allowedtypes.length;ctr++)
		{
			
			if(allowedtypes[ctr] == fileext)
			{
				return true
			}		
		}
		alert("Only JPG/JPEG/GIF type picture files are allowed.\n Please select a valid file type.")	

	}
	else
	alert("The file you have selected is not a valid picture file.\nPlease select a different file.")
	
	return false
}