var yes = 0;
var no = 1;
var enabled = 0;

var trench_runs = new Array();
trench_runs[0] = yes;
trench_runs[1] = no;
trench_runs[2] = no;
trench_runs[3] = no;
trench_runs[4] = no;

function addNewRun(obj)
{
	var i;
	var j;

	var k;
	var l;
	//alert(trench_runs.length);
	for(i=0; i<trench_runs.length; i++)
	{	
		j = i+1;
		if (trench_runs[i] == no)
		{
			trench_runs[i] = yes;
			MM_swapImage('but_trench'+j,'','images/but_trenchform_tab'+j+'a.gif',1);
			MM_swapImage('but_trench'+i,'','images/but_trenchform_tab'+i+'.gif',1);
			MM_showHideLayers('trench'+i,'','hide','trench'+j,'','show');
			break;
		} else {
			MM_swapImage('but_trench'+j,'','images/but_trenchform_tab'+j+'.gif',1);
			MM_showHideLayers('trench'+j,'','hide');
		}

		if (i>=trench_runs.length-2) {
			obj.disabled=true;	
		}
	}
	document.myform.tottab.value=i;
}

function jump( trench )
{
	var i;
	var j;
	
	if (trench_runs[trench] == yes) {
		for (i=0; i<trench_runs.length; i++)
		{
			j = i+1;
			if (trench_runs[i] == no)
			{
				MM_swapImage('but_trench'+j,'','images/but_trenchform_tabblank.gif',1);
			} else {	
				MM_swapImage('but_trench'+j,'','images/but_trenchform_tab'+j+'.gif',1);
			}
			MM_showHideLayers('trench'+j,'','hide');
		}
		MM_showHideLayers('trench'+(trench+1),'','show');
		MM_swapImage('but_trench'+(trench+1),'','images/but_trenchform_tab'+(trench+1)+'a.gif',1);
	}	
}