function calcul_art1(){
		var tr_a1 = Number(document.getElementById("trdeprix_a1").value);
			if (tr_a1==1) {
				var p1_a1 = Number(document.getElementById("p1_a1").value);
				var q_a1 = Number(document.getElementById("q_a1").value);
					if (q_a1>=1) {
						var p_a1 = Number(p1_a1);
						var total_a1 = Number(p_a1 * q_a1);
						document.getElementById("total_a1").value = total_a1.toFixed(2);
						var ttc_a1 = Number(total_a1 * 1.196);
						document.getElementById("ttc_a1").value = ttc_a1.toFixed(2);
						}
				}
			else if (tr_a1==2) {
				var s1_a1 = Number(document.getElementById("seuilp1_a1").value);
                var p1_a1 = Number(document.getElementById("p1_a1").value);
				var p2_a1 = Number(document.getElementById("p2_a1").value);
                var q_a1 = Number(document.getElementById("q_a1").value);
					if (q_a1>=0 && q_a1<s1_a1) {
						var p_a1 = Number(p1_a1);
						var total_a1 = Number(p_a1 * q_a1);
						document.getElementById("total_a1").value = total_a1.toFixed(2);
						var ttc_a1 = Number(total_a1 * 1.196);
						document.getElementById("ttc_a1").value = ttc_a1.toFixed(2);
						}
					else {
						var p_a1 = Number(p2_a1);
						var total_a1 = Number(p_a1* q_a1);
						document.getElementById("total_a1").value = total_a1.toFixed(2);
						var ttc_a1 = Number(total_a1 * 1.196);
						document.getElementById("ttc_a1").value = ttc_a1.toFixed(2);
						}
				}
			else if (tr_a1==3) {
				var s1_a1 = Number(document.getElementById("seuilp1_a1").value);
				var s2_a1 = Number(document.getElementById("seuilp2_a1").value);
                var p1_a1 = Number(document.getElementById("p1_a1").value);
				var p2_a1 = Number(document.getElementById("p2_a1").value);
				var p3_a1 = Number(document.getElementById("p3_a1").value);
                var q_a1 = Number(document.getElementById("q_a1").value);
					if (q_a1>=0 && q_a1<s1_a1) {
						var p_a1 = Number(p1_a1);
						var total_a1 = Number(p_a1 * q_a1);
						document.getElementById("total_a1").value = total_a1.toFixed(2);
						var ttc_a1 = Number(total_a1 * 1.196);
						document.getElementById("ttc_a1").value = ttc_a1.toFixed(2);
						}
					else if (q_a1>=s1_a1 && q_a1<s2_a1) {
						var p_a1 = Number(p2_a1);
						var total_a1 = Number(p_a1 * q_a1);
						document.getElementById("total_a1").value = total_a1.toFixed(2);
						var ttc_a1 = Number(total_a1 * 1.196);
						document.getElementById("ttc_a1").value = ttc_a1.toFixed(2);
						}
					else {
						var p_a1 = Number(p3_a1);
						var total_a1 = Number(p_a1 * q_a1);
						document.getElementById("total_a1").value = total_a1.toFixed(2);
						var ttc_a1 = Number(total_a1 * 1.196);
						document.getElementById("ttc_a1").value = ttc_a1.toFixed(2);
						}
				}
    }