function check()
{
    if(Trim(document.f1.txtEmail.value)=="")    
    {
        alert('Please Enter Email-Id');
        document.f1.txtEmail.focus();
        return false;
    }
    if(!echeck(document.f1.txtEmail.value))
    {
        return false;
    }
    document.f1.action="CaptureData.asp";
    document.f1.submit();
    
}
function echeck(str) 
{
	var at="@"
	var dot="."
	var lat=str.indexOf(at)
	var lstr=str.length
	var ldot=str.indexOf(dot)
	if (str.indexOf(at)==-1)
	{
		alert("Invalid E-mail ID")
		return false
	}
	
	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr)
	{
		alert("Invalid E-mail ID")
		return false
	}
	
	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr)
	{
		alert("Invalid E-mail ID")
		return false
	}
	
	if (str.indexOf(at,(lat+1))!=-1)
	{
		alert("Invalid E-mail ID")
		return false
	}
	
	if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot)
	{
		alert("Invalid E-mail ID")
		return false
	}
	
	if (str.indexOf(dot,(lat+2))==-1)
	{
		alert("Invalid E-mail ID")
		return false
	}
	
	if (str.indexOf(" ")!=-1)
	{
		alert("Invalid E-mail ID")
		return false
	}
	if ((str.indexOf("..")>-1) ||(str.substring(str.length-1,str.length)==dot))
	{ 
		alert("Invalid E-mail ID")
		return false
	}    
	return true					
}

    function Trim(TRIM_VALUE) {
        if (TRIM_VALUE.length < 1) {
            return "";
        }
        TRIM_VALUE = RTrim(TRIM_VALUE);
        TRIM_VALUE = LTrim(TRIM_VALUE);
        if (TRIM_VALUE == "") {
            return "";
        }
        else {
            return TRIM_VALUE;
        }
    } //End Function

    function RTrim(VALUE) {
        var w_space = String.fromCharCode(32);
        var v_length = VALUE.length;

        var strTemp = "";
        if (v_length < 0) {
            return "";
        }
        var iTemp = v_length - 1;

        while (iTemp > -1) {
            if (VALUE.charAt(iTemp) == w_space) {
            }
            else {
                strTemp = VALUE.substring(0, iTemp + 1);
                break;
            }
            iTemp = iTemp - 1;

        } //End While
        return strTemp;

    } //End Function

    function LTrim(VALUE) {
        var w_space = String.fromCharCode(32);
        if (v_length < 1) {
            return "";
        }
        var v_length = VALUE.length;
        var strTemp = "";

        var iTemp = 0;

        while (iTemp < v_length) {
            if (VALUE.charAt(iTemp) == w_space) {
            }
            else {
                strTemp = VALUE.substring(iTemp, v_length);
                break;
            }
            iTemp = iTemp + 1;
        } //End While
        return strTemp;
    } //End Function